Perkin-Elmer SF Series Operation And Maintenance Download

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Summary of Contents for SF Series

Page 1: ...301462 002 PERKIN ELMER Memory Products Division SUPER SERIES SF AND ST MAGNETIC DISK DRIVE OPERATION AND MAINTENANCE VOLUME 1 ...

Page 2: ...Pr8nted In U S A PERKIN ELMER Memory Products Division SUPER SERIES SF AND ST MAGNETIC DISK DRIVE OPERATION AND MAINTENANCE VOLUME 1 ...

Page 3: ... available Figure Title 3 3 Series T Cartridge Loading 5 3 Front Load with Cover Removed 5 4 Top Load with Cover Removed 5 5 Assy Identification Bottom View 5 7 Simplified Front View 5 10 Power Supply Assy Appendix A A Master Spares List was not available This release also covered 1500 and 2400 rpm 2200 BPI machines only how ever all drawings misssing from Appendix B in the Preliminay Release were...

Page 4: ... machines SECTION 4 Writeups were added as required to cover the Data Control MFM PWB which also required two new illustrations one for Read one for Write SECTION 5 Writeups were added as required to cover the Data Control MFM PWB which also revised Detent Waveform Figures 5 33 and 5 34 Throughout Section 5 grid coordinates were added to test point references as an assist for technicians in the fi...

Page 5: ...d Figure 5 35 Fine Offset Adjustment Chart of Figure 5 36 Temp Compensation Voltage Chart deleted Data now in new Table 5 4 APPENDIX B ENGINEERING DWGS AND MATL LISTS Updated Dwgs 400000 Disk Drive 100 200 TPI ST A B 301457 Detent Amplifier PWB B C 301483 SVA E G 301636 EIB A B 301650 Spindle Drive Limiter PWB and Schematic A B 301206 DEB D F 301632 DCB C E and 301047 Line Terminator PWB 031 33 Fe...

Page 6: ... Appendix B Commutator PWB 301170 replaced by 301920 I O Connector D 40 PWB 301453 replaced by 301936 Spindle Drive Limiter 5V Drive PWB 301650 replaced by 301794 Spindle Switch PW8 301653 replaced by 301789 Updated Disc Drive ST 400000 8 C Disk Drive SF 400001 8 C Line Terminator D31 33 Female 301047 8 C Line Terminator D31 33 Male 301055 8 C CIB 301174 8 C DEB 301206 F G I O 301291 A A1 DIB VFO ...

Page 7: ...ated Disk Drive ST 400000 C E Disk Drive SF 400001 C D I O Connector 031 33 301062 B C C1 B 301174 C C1 DEB 301206 G H Power Supply 301361 C D MFM 301422 C C1 EIB 301636 E F SLB 301687 C B Spindle Switch 301789 B B1 Spindle Limiter 5V Drive 301794 A B 1 Commutator 301920 A B and I O PWB D40 301936 A B Added Emergency Retract 302064 Appendix C Updated DEB 301207 E F Power Supply 301361 C D and DCB ...

Page 8: ...s S T 400000 E F S F 400001 D E Line Term D40 Male 301074 B C DEB 301206 H J DCB 301632 E G EIB 301636 G H Spind Lim 5V 301794 B C I O D 40 301936 B C APPENDIX C Updated Schematics DCB 301633 D F I O D40 A B APPENDIX D Page D 15 Item 1 PIN changed Page D 25 Items 2 and 7 PIN changed Page D 26 Figure D 1 0 Items 36 37 and 40 deleted from Brush Access Cover hardware Page D 27 Items 1 and 34 P N chan...

Page 9: ... 4 8 last paragraph and paragraph 4 5 3 4 4 SECTION 5 Revised Paragraph 5 5 5 2 and 5 5 5 5 Added new Figure 5 36 ACN 1478 APPENDIX B Updated Disk Drive ST 400000 F G Disk Drive SF 400001 E F CIB 301174 C D PS 301361 D E SVA 301483 L M APPENDIX C Updated CIB 301175 D E PS 301361 D E SVA 301484 J K APPENDIX D lPB E 001 Data and the Low ImpedanceAddendum deleted from manual To be supplied on request...

Page 10: ...A 1 Item 1 Mag Rec Hd for 4400 BPI R W 301401 001 and 002 changed to 301489 005 and 006 APPENDIX B Updated Disk Drive 100 200 TPI ST 400000 G L DiskDrive 100 200 TPI SF 400001 F K Control Interface PWB 301174 D E Data Electronics PWB 301206 J K Servo Amplifier PWB 301483 M N Electronic Interconnect PWB 301636 J K Spindle Drive Limiter 5V Drive PWB 301794 D E I O Connector D40 301936 C D 1 APPENDIX...

Page 11: ...ENDIX C Added I O Connector WII nterrupt Option 301948 A Piggyback I O Connector With Interrupt Option 301953 A Revised manual for two volume split Volume 1 contains all text and associated art in five sections Volume 2 contains logic schematics PWB assembly drawings and material lists and a Master Spare Parts List SECTION 1 Revised completely SECTION 3 Added Paragraph 3 4 and Figures 3 6 through ...

Page 12: ...RECORD OF REVISIONS Revision Description Date R SECTION 5 ACN 71279 11 79 Revised Page 5 79 paragraph 5 5 13 1 Revised Page 5 80 Figure 5 43 xi ...

Page 13: ...nts 2 3 2 4 2 Interface Requirements 2 5 2 4 3 Electrical Characteristics 2 9 2 4 4 Input Lines 2 9 2 4 5 Output Lines 2 10 2 4 6 Rack Mou nted Installation 2 12 2 4 7 Initial Checkout 2 14 3 OPERATION 3 1 SCOPE 3 1 3 2 OPERATOR CONTROL PANEL 3 1 3 2 1 Functions of Operator Panel Controls 3 2 3 3 CARTRIDGE LOADING 3 3 3 3 1 SF Disk Drive 3 3 3 3 2 ST Disk Drive 3 7 3 3 3 Operating the Disk Drive 3...

Page 14: ... MAINTENANCE 5 3 5 3 1 Preventive Maintenance Schedule 5 3 5 3 2 ReadlWrite Head Inspection and Cleaning 5 4 5 3 3 Fixed Disk Cleaning 5 5 5 3 4 Cartridge Removal and Handling 5 5 5 3 5 DiskDrive Top Cover Removal 5 7 5 4 CORRECTIVE MAINTENANCE 5 7 5 4 1 General Description 5 7 5 4 2 Removal and Replacement of Major Assemblies 5 16 5 4 3 Removal and Replacement of Subassemblies 5 27 5 5 ADJUSTMENT...

Page 15: ...s 4 5 Positioner Assembly 4 6 Optical Transducer Diagram 4 7 Movable Optical Glass 4 7 ReadIWrite Heads 4 9 Head Unloading Mechanism 4 10 Block Diagram Super Series major signal lines 4 13 Block Diagram Super Series major signal lines 4400 BPI only 4 14 Functional Block Diagram Head Positioning System 4 15 Functional Block Diagram Read Write Circuit 4 16 Block Diagram I O Board 4 18 Spindle Motor ...

Page 16: ... Brush Mounting 5 33 Spindle Shaft Ground Brush Mounting 5 34 Disk Cleaning Brushes Installation Replacement Guide 5 34 Cartridge Interlock Switch Assembly 5 35 Removable Index Sector Transducer Series F Only 5 37 Fixed and Removable Index Sector Transducer 5 38 Read Write Head Assembly 5 40 Torque Wrench No T 00425 Application 5 42 Emergency Retract PWB Assembly 5 44 Power Supply Connections Comm...

Page 17: ... Interface Pin Assignments 2 5 Printed Wiring Board Acronyms 2 6 Glossary of Mnemonic Terms 2 7 Normal Run Switching Sequence 4 55 Preventive Maintenance Schedule 5 2 Standard and Special Accessories and Service Aids 5 14 Table of Adjustments 5 46 Temperature Compensation Voltage 5 68 CE Cartridge Head Alignment Tracks 5 75 Fault Isolation Chart 5 84 xvi ...

Page 18: ......

Page 19: ...Front Load Series SF Top Load Series ST Frontispiece Super Series Magnetic Disk Drives ...

Page 20: ...op loading ST 100 or 200 tracks per inch TPI tracks per 2 54 cm random access high capacity data storage devices whose compact size optimum performance and reliability make them exceptionally suitable for use in computer sys tems of small and medium size Several models are available in each series with a choice in storage capacities and transfer rates In standard versions the units incorporate in ...

Page 21: ...ral assembly thus eliminating a drive belt and pulleys B The spindle motor is a DC brushless unit and its speed is held constant within 1 percent regardless of line voltage and frequency fluctuations Therefore the storage of data in any given sector of the disks can be maximized C Either of two spindle speeds are available 1500 or 2400 rpm 4400 BPI available at 2400 rpm only D The head positioning...

Page 22: ...CATORS Controls and associated status indicators are located on a panel below the plastic door These in clude the switches with which the operator starts and stops the Disk Drive selects the unit address in multiple disk drive installations and write protect indicator switches for both the removable and fixed disks The function and operation of each switch and indicator is described in Section 3 1...

Page 23: ...artridge Series SF IBM 2315 type IBM 2315 type Cartridge Series ST IBM 5440 type IBM 5440 type modified IBM Built in Power Supply 3300 type media for 4400 BPI Requirements 100 110 120 130 200 100 110 120 130 200 220 220 230 240 250 260 230 240 250 260 VAC VAC 10 47 63Hz 10 47 63Hz 250 VA 250 VA Physical Dimensions Height Series SF 7 00 in 17 78cm 7 00 in 17 78cm Height Series ST 7 75 in 19 68 cm 7...

Page 24: ...n 4 1 4 5 HEAD POSITIONE R ASSEMB LY The head positioner mechanism positions the read write heads over the selected cylinder track on the fixed or removable disk The head positioner assembly contains the following components an electromagnetic linear actua tor carriage carriage guides head loading unloading cams and a positioner transducer All com ponents of the head positioner form an integral as...

Page 25: ...xible cables 1 5 FORCED AI R CLEANING SYSTEM The SF and ST Disk Drives contain a forced air system that purges the disk and head areas with highly filtered air Air is drawn from outside the cabinet and cools the electronic assemblies During operation the interior of the disk drive is at slightly elevated pressure with respect to the ambient which serves to keep dust from entering the disk drive Th...

Page 26: ...bag All of these components should be saved in case it may be necessary to relocate the unit at a later date A shipping package PIN T 00287 may be ordered from the Company When the plastic bag has been removed grip the unit along both sides of the casting while lifting it out of the container Do NOT support the unit by the handle on the front panel The finished surfaces and the plastic part of the...

Page 27: ...SUPER SERIES 1088 002 12 PACKING LIST ENVELOPE Figure 2 1 Shipping Container and Parts 2 2 ...

Page 28: ...range from 47Hz to 63Hz The appropriate input connections are established via a voltage selection plug located next to the power transformer PRIOR TO CONNECTING THE AC LINE CORD TO THE POWER SOURCE VERIFY THAT THE VOLTAGE PLUG IS COMPATIBLE WITH THE LINE VOLTAGE AT THE INSTALLATION SITE EXAMINE THE POWER SPECIFICATION DECAL ON THE REAR PANEL OF THE UNIT If the transformer tap connections are chang...

Page 29: ...POSITIONED ON RETRACT SWITCH ACTUATOR a INSTALLED POSITION b STOWED POSITION RESTRAINT RETAINING SCREW SHIPPING RESTRAINT Figure 2 2 Carriage Shipping Bestraint 2 4 1089 002 ...

Page 30: ...yl Add 24 45 Illegal Address 13 Cyl Add 25 47 Attention Unit 0 20 Cyl Add 26 48 Attention Unit 1 17 Cyl Add 27 50 Attention Unit 2 19 Cyl Add 28 29 Attention Unit 3 18 Cyl Add Strobe 32 Read Data 7 Restore 38 Data Clock 8 Disk Select 31 Index 9 Head Select 33 Sector 6 Write Gate 36 Sector Address 20 4 Erase Gate 40 Sector Address 21 2 Write Data 41 Sector Address 22 26 Read Gate 49 Sector Address ...

Page 31: ... No 57 10500 27 Perkin Elmer PN 101036 001 The corresponding mating connector for the cable is Amphenol No 57 20500 31 Perkin Elmer PN 101037 001 and is supplied with the drive I O signal cables are 28 AWG twisted pairs Total system cable length should not exceed 50 feet 15 24 meters or 30 feet 9 144 meters for 4400 BPI An AC power cable Perkin Elmer PN 101153 and all described cables are supplied...

Page 32: ...roller DLY SK Delay Seek SLB EOT End of Travel pulse Detent Amplifier board FIDX Fixed Disk Index pulse DCB FSTR Fixed Disk Sector pulse DCB FWD Forward direction of Positioner movement SLB HD SEL Head Select decode signal Controller I LL ADD Illegal Address decode signal SLB NAR New Address Register SLB RDY Ready signal to Controller CIB RDYINH Ready Inhibit SVA RIDX Removable Disk Index pulse DC...

Page 33: ...SUPER SERIES I O BOARD TERMINATOR BOARD 1294 001 I O CONNECTOR J 22 DAISY CHAIN CONNECTOR J 23 Figure 2 4 Rear Panel and I O Connector 90ard 2 8 ...

Page 34: ... 3 4 Logic Levels Logic 0 within the drive is defined as a level between 0 and 0 5 V 2 4 4 INPUT LINES All input lines are defined as being true active when at logic 0 level 2 4 4 1 Cylinder Address Eight nine on 200 TPI lines which accept an absolute address from the controller These are strobed into an address register by the Cylinder Address Strobe Line 2 4 4 2 Cylinder Address Strobe One line ...

Page 35: ... 2 4 4 10 Track Offset Fwd Available on 200 TPI Only One line which causes the heads to move 1 10 track 2 4 4 11 Track Offset Rev Available on 200 TPI Only One line which causes the heads to move 1 10 track 2 4 4 12 Unit Select Four lines used in conjunction with the Unit Select Switch which allows any drive to be given any of four logical addresses 2 4 5 OUTPUT LI NES All outputs are defined as b...

Page 36: ...n the fixed disk hub This hub is selected with Disk Select Optionally when the internal sector counter is not specified the user may specify two index lines In that case both index marks are supplied simultaneously and they are not selected by Disk Select 2 4 5 10 Sector Pulse This line supplies one pulse for each notch on the cartridge hub or for the fixed disk hub one pulse for every nth notch n...

Page 37: ...ers of the slides as shown in Figure 2 5 Therefore this panel will remain at the rear of the rack or cabinet when the Disk Drive is pulled out on its slides A flexible flat cable assembly internal to the Disk Drive provides the I O line connections between the I O Connector board and the Disk Drive Similarly a spiral wound AC cord provides the power connection These features facilitate unrestricte...

Page 38: ... 1_9 6_9CM t r Jrt _18 31 IN _ 0 625 IN NOTES CLOSED 46 00 IN 116 84 CM OPEN BOTTOM 0 875 IN 46 51 CM 1 5B8 CM PROPE RTY 1 223 CM 4 PLACES LINE 4 PLACES 1 IF 30 00 IN 7620 CM DEEP CABINET IS USED POSITION REAR RETMA BOLT RAILS 22 00 IN TO 23 00 IN 55 88 CM TO 58 42 CM BEHIND FRONT RAILS 2 SLIDE MOUNTING BRACKETS ARE NORMALLY MOUNTED ON EXTERIOR SIDE OF CABINET Figure 2 5 Rack Mounted Installation ...

Page 39: ...a customer engineer C E test hub the top cover interlock switch will not be activated Power cannot be applied to the Spindle Drive Motor In the SF unit this is a button type switch protruding from the base Place a piece of masking tape over the switch In the ST unit install a matchbook cover or simi lar device between pack sensor and switch actuRt or See Figure 2 6 2 4 7 4 sequencing l ENSURE PLUG...

Page 40: ...figure 2 6 By_passing lOP cover InterloCK switch 2 15 ...

Page 41: ......

Page 42: ...ONTROL PANEL Operational controls and status indicators are mounted on a panel located on the front of the Disk Drive Some of the controls feature integral indicator lamps which if activated illuminate the translucent engraved control pushbuttons The control cluster is shown in Figure 3 1 and individual functions of the controls and indicators are described in paragraphs 3 2 1 1 through 3 2 1 6 SU...

Page 43: ... unit is able to accept Seek or Data Commands from the external Controller When the LOAD portion of the switch lights the operator is notified that the spindle has stopped rotating At this time the removable disk cartridge can be loaded or unloaded 3 2 1 4 Protect Cartridge Disk Switch I ndicator This switch indicator is a two position rocker switch marked PROT CART When pressed upward the switch ...

Page 44: ...D TO THE DISK DRIVE OR THE DOOR ASSEMBLY MAY BE DAMAGED WHEN THE POWER AND LOAD INDICA TORS ARE I LLUMINATED THE INTER LOCK IS RELEASED AND THE DOOR CAN BE OPENED EASI LY NOTE The 2200 and 4400 BPI cartridges are keyed differently To load the cartridge perform the following steps A Apply power to the Disk Drive by pressing the POWE R switch Observe that the lamp inside the switch indicator lights ...

Page 45: ...1116 Figure 3 2 SF Disk Drive Cartrldge Loading 3 4 ...

Page 46: ...Figure 3 3 ST Disk Drive Cartridge Loading 3 5 ...

Page 47: ...BEGIN COMPUTER OPERATIONS YES REMOVE INCORRECT CARTRIDGE INSTALL PROPER JOB CARTRIDGE 1117 001 YES TURN RUN LOAD SWITCH TO LOAD Figure 3 4 Operating the SF or ST Disk Drive 3 6 ...

Page 48: ...cally as the unit slides out C Before the cartridge can be inserted its bottom cover must be removed Raise the cartridge handle to a vertical position while pushing the release button side ways D The bottom cover is then released and can be remdved It will be installed later on top of the cartridge E Orient the cartridge so that the cartridge logo or letters are facing the front of the Disk Drive ...

Page 49: ...o events should occur A Power and Load indicator lamps should light B The loading door should unlock At this time the removable cartridge may be removed from or inserted into the Disk Orive NOTE Inspect the cartridge for dirt or contamination before installing in Disk Drive 3 3 3 2 Establishing the Ready Status from the Load Status To initiate this operation transfer the RUN LOAD switch from LOAD ...

Page 50: ...pproximately 15 seconds D The loading door should unlock At this time the cartridge may be removed and replaced or power to the Disk Drive may be re moved NOTE When the cartridge is removed from an ST Disk Drive it should be placed in its cover immed iately to preclude damage to or contamination of the cartridge On an SF Drive the cartridge should be stored in a clean environment and handled in a ...

Page 51: ...EADY INDICATOR SEEK COMPLETE t _____ j r APPROXIMATELY 5 SEC I I t t I l 25 SEC _ _ 1 I tr 1 j r SEE NOTE 1 rll _____I U __________ l NOTE 1 ELAPSED TIME IS DETERMINED BY THE TIME IT TAKES FOR A TEMPERATURE MATCH TO OCCUR BETWEEN BASEPLATE AND CARTRIDGE DISC Figure 3 5 Power On Off Sequence 3 3 5 TEMPERATURE CHARACTERISTICS When operating the Disk Drive the casting temperature near the location of...

Page 52: ...re shown in Figures 3 6 through 3 12 NO AC POWER IS AVAILABLE TO DRIVE AC POWER AVAILABLE TO POWER SUPPLY DC POWER AVAILABLE TO ELECTRONICS LOAD LIGHT ON LATCH ASSEMBLY ACTUATES REMOVE REPLACE CARTRIDGE 0418 NO Figure 3 6 Power up and Cartridge Loading Load Mode ...

Page 53: ...NO NO NO NO POWER UP SEQUENCE COMPLETED POWE R APPLI ED TO DRIVE BRUSH MOTORS Figure 3 7 Run Mode Initial Cycle 3 12 0420 ...

Page 54: ...ENABLE POWER AMPLIFIER CARRIAGE MOVES FORWARD NO FIRST TRACK COUNTING PULSE RESETS NAR CAR TO 0 DETENTS NO READY LIGHT ON Figure 3 8 Run Mode Cylinder 000 Seek 3 13 0417 2 ...

Page 55: ... TIMER YES YES NEW ADDRESS COMPARED WITH CAR DIRECTION VELOCITY INFORMATION GENERATED BY SERVO ELECTRONICS IS SENT TO POSITIONER COARSE LOOP SERVO DE ENERGIZED FINE LOOP SERVO DETENT ENERGIZED START 5 MS SEEK COMPLETE TIMER NO SEEK COMPLETE ISSUED YES Figure 3 9 Run Mode New Address Seek 3 14 SEEK INCOMPLETE ISSUED CARRIAGE RETURNS TO TRACK 0 NEXT SEEK PULSE RESETS SEEK INCOMPLETE LINE 0419 ...

Page 56: ...0416 YES NO YES YES YES NO Figure 3 10 Run Mode Write Operation 3 15 ...

Page 57: ...UNIT SELECTED DISK SELECTED READ DATA SUPPLIED TO DATA DISCRIMINATOR READ OPERATION COMPLETE 0421 NO Figure 3 11 Run Mode Read Operation 3 16 ...

Page 58: ...FILE OPERATIONAL READY LIGHT OFF CARRIAGE RETURNS HOME LOAD LIGHT ON INTERLOCK OPENS REMOVE R EPLACE CARTRIDGE NO NO Figure 3 12 Turn off Cycle 3 17 422 2 ...

Page 59: ......

Page 60: ...bly The electronic part is further sub divided into System Electronic Theory Logic Board Circuit Analysis and Schematic Diagram Analysis The simplified block diagram for the Disk Drive is shown in Figure 4 1 4 3 MECHANICAL DESCRIPTION 4 3 1 SPINDLE DRIVE MOTOR ASSEMBLY The spindle drive motor is combined into an integral assembly as shown in Figure 4 2 The spindle is directly driven by a DC brushl...

Page 61: ...LECTRONICS INTERCONNECT BOARD MOTHER BOARD SERVO AMPLIFIER BOARD SVA FROM READ WRITE HEADS DATA ELECTRONICS BOARD DEB SERVO LOGIC BOARD SLB CONTROL INTERFACE BOARD CIB DATA INTERFACE OR MFM BOARD DIB OR MFM Figure 4 1 Simplified Block Diagram 4 2 I I I I I I I 1119 001 I O 1 _ CONNECTOR 1 BOARD I lOB I I I I I I I TO EXTERNAL CONTROLLER ...

Page 62: ...0203 001 DISK SPINDLE SHAFT MAGNETIC RING FIXED DISK SECTOR RING W SLOTS Figure 4 2 Spindle Drive Motor Assembly 4 3 ...

Page 63: ...ads mount on the carriage assembly which rides on ball bearings over precision Juide rails Extending or retracting the carriage along the guide rails moves the heads radially across the disk surface An optical position transducer produces analog signals necessary for moni toring head position and detent operations This unit contains a light emitting diode LED lens and reticle assembly The reticle ...

Page 64: ...KSECTOR RING SECTOR SLOT INDEX SLOT SECTOR SLOT INDEX SLOT b TOP LOADING CARTRIDGE DISKSECTOR RING c FRONT LOADING CARTRIDGE DISK SECTOR RING WITH DUST COVERS REMOVED Figure 4 3 Three Types of Sector Rings 4 5 0832 001 RECORDING SURFACE ...

Page 65: ...SUPER SERIES CARRIAGE Assembly 4 4 Positioner Figure 4 6 1093 2 003 ...

Page 66: ... IES OUTPUT WAVESHAPE LED LIGHT SOURCE _ POS CH MOVABLE ETCHED OPTICAL GLASS Figure 4 5 Optical Transducer Diagram CARRIAGE DIRECTION 112O oo2B TOSVA 0873 001 _ _ _ 1 BOT EOT Figure 4 6 Movable Optical Glass 4 7 ...

Page 67: ...rformed by circuits associated with the Read or lVrite operations are included in the discussions of these circuits as associated with the circuit analysis descriptions The ReadIWrite heads are automatically unloarled during a power down procedure and are auto matically loaded when the RUN switch on the Operator Control Panel OCP is actuated The ReadIWrite heads are ramp loaded a technique requiri...

Page 68: ...SUPER SERIES CERAMIC SHOE BLEED HOLES GIMBAL SPRING 1121 001 RAMP Figure 4 7 Read Write Heads 4 9 ...

Page 69: ...SUPER SERIES 1122 001 SPRINGS Figure 4 8 Head Unloading Mechanism 4 10 ...

Page 70: ...agram of the Disk Drive can be referred to see Figure4 1 The mechanical operation theory also should be used as a reference 4 4 1 3 Basic System Operation When the POWE R switch on the OCP is pressed control circuits registers and counters are preset to a desired initial state The applicable DC working voltages are generated and the circuits which drive the DC spindle drive motor are enabled Note ...

Page 71: ...AND GENERATES A SIGNAL PROPORTIONAL TO THE NUMBER OF TRACKS THE HEAD POSITIONER HAS TO MOVE ALSO CONTAINS SOME TEMPERATURE COMPENSATING CIRCUITRY ADD 256 128 TEMPERATURE SENSOR SENSES TEMPERATURE OF BASE CASTING AND COMPENSATES HEAO POSITION AS REQUIREO TCV I D C B TCOAC BEGINNING OF TRAVEL PULSE FWD REV EN IL LOAD UNLOAD I DIF 256 128 I I o DAC SERVO DET EN FWDH ODD DETENT ODD DETENT EVEN FWD INH...

Page 72: ...ROLLER IN SEPARATE READ WRITE CHANNELS DATA CLOCK PROVIDES WRITE PROTECT LOGIC TO ENSURE DATA IS NOT ERASED INADVERTENTLY READ ENABLE ALSO REGULATES 13V I _WRITE READ WRITE HEADS READ 4 LINES MOTOR POSITIONS READ wRITE HEADS VELOCITY TRANSDUCER SENSES VELOCITY OF POSITIONER MOTOR AND REPORTS INFOR 1 MATION TO SERVO AMPLIFIER I EN DR ENABLE DRIVERS ILLEGAL ADDRESS ADDRESS ACKNOWLEDGE ATTENTION CONT...

Page 73: ...L PROPORTIONAL TO THE NUM8ER OF TRACKS THE HEAD POSITIONER HAS TO MOVE ALSO CONTAINS SOME TEMPERATURE COMPENSATING CIRCUITRY ADD 256 128 TEMPERATURE SENSOR SENSES TEMPERATURE OF BASE CASTING AND COMPENSATES HEAD POSITION AS REQUIRED TCV IDCB TC DAC BEGINNING OF TRAVEL PULSE COARSE SERVO EN IL LOAD UNLOAD 1 DIF 256 128H D DAC SERVO DET EN H FWDH ODD 1 DETENT ODD H DETENT EVEN H FWD INHIBIT DIFF lIL...

Page 74: ...COMPLETE F INDEX CONTAINS SECTOR R SECTOR COUNTERS AND MISC R INDEX CONTROL CIRCUITRY REQUIRED TO TRANS FER SIGNALS TO THE NO omv CONTROLLER READY I O LIMITER MODULE CONNECTOR AND POWER SPINDLE BOARD lOB SWITCH MOTOR LINE DRIVERS PROVIDES SPINDLE MOTOR CURRENT SECTOR ADDRESS TO 1 32 RIW 4 HEADS t SPINDLE TO INDEX SECTOR t DISKS SECTOR TRANSDUCERS BRUSH J BRUSHES I MOTOR INDEX WRT CHK X I 1 DISK SE...

Page 75: ...ining the binary value representing the present positioner carriage location These two values are compared and a difference value is obtained which represents the difference between these two binary numbers This difference value is applied to a D A converter to provide an analog drive signal which is sent to the Servo Amplifier Board A simplified block diagram of the head positioning system is sho...

Page 76: ... the SEE K CaMP signal is received by the Controller a Read or VVrite operation may be initiated A functional block diagram showing the logic circuits associated with Read and Nrite operations is shown in Figure 4 12 Head selection determines which surface upper or lower will be written on or read from A decoding matrix on the Data Electronics Board DEB will deter mine whether the fixed or cartrid...

Page 77: ...re routed to the Electronics Interconnect Board E IB through connector J20 and the flexible intercon necting ribbon cable assembly 4 5 1 3 Line Drivers The status and data signals generated in the Disk Drive are routed to the lOB from J20 through the ribbon cable and connector J21 Each signal is routed to one input of the corresponding line driver The second input to each line driver is a common e...

Page 78: ...DR 4 _ RDY RDY I LL ADD ILL ADD ADD ACK ADD ACK EN DR ___ o ATTENTION TO CONTROLLER 1 ATTENTION 2 ATTENTION 3 ATTENTION SEEK COMP EN DR I I UNIT SELECT NO 0 UNIT SELECT NO 1 UNIT SELECT NO 2 Yr 4 EN RECV UNIT SELECT NO 3 CL RESTORE SEEK STROBE FROM CONTROLLER DAISY CHAIN CONNECTOR Figure 4 13 Block Diagram I O Board Sheet 1 of 2 4 19 ...

Page 79: ... 112SB 001 J21 EN DR SH 1 J23 J22 STRISAC 32 SAC 16 F STR SAC S F lOX lOX CONTROLLER SAC 4 SAC 2 SAC 1 DATA CLK WRT CHK X WRITE DATA RD EN GATE READ DATA HEAD SEL CONTROLLER DISK SEL WRITE PROT ERASE GATE WRITE GATE Figure 4 13 Block Diagram I O Board Sheet 2 of 2 4 20 ...

Page 80: ...onding pin daisy chain connector J23 a female recep tacle mates with one end of a daisy chain cable whose other end mates with I O connector J22 of the second Disk Drive etc Up to four drives can be interconnected with the Controller in this manner The daisy chain cable will be terminated in the end unit by inserting a terminator plug into J23 Circuitry is provided to disable Output Drivers when o...

Page 81: ... SP MOTOR ON CONTROL TO MOTOR to LOGIC RTZ RETRACT LOGIC 4 TO SLB FIDX Figure 4 14 Spindle Motor Speed Detection and Control Functional Block Diagram A simplified logic diagram and a timing diagram are provided in Figures 4 15 and 4 16 respectively Two of the inputs to AN D gate A see Figure 4 15 are 5V and the output of the DC LOSS TI ME R one shot During normal operation these inputs will be hig...

Page 82: ...COUNT 2000 FF L COUNT 2020 FF __________________________________________________ r__l __________ COUNT 2048 FF FIDX _ _ _ _ _ n ______ In ______ In ______rL SP DETEC FF _ _____ k DECREASE SPEED SPM ON FF J INCREASE SPEED RDY1 t RDY 1 GOES FALSE RTZ Figure 4 16 Motor Speed Control Timing Diagram 4 23 ...

Page 83: ...and its Q output input to NAND gate B see Figure 4 15 will either allow or inhibit spindle motor drive current This pulsing of the spindle motor is the method employed to maintain spindle disk speed at a constant rpm 1 percent 4 5 3 3 Index and Sector Pulse Separation Nhen the Sector pulse that preceeds the Index pulse arrives it will after shaping fire the lOX OATA Timer See Figures 4 17 and 4 18...

Page 84: ... RI OX t I RSTR Figure 4 17 Removable Disk Index Sector Separation i1 6MS I 61 0 jJS I 1MS 1 6MS 1 6MS NOTE 1500 RPM UNIT WITH 24 SECTOR RING TIMING IS SAME FOR SF AND ST BUT OUTPUT OF TRANSDUCER WILL BE DIFFERENT 0875 FM XDUCER U SCHMIDT TRIGGER Fi ure 4 18 Removable IDX STR Pulse Timing Diagram 4 25 ...

Page 85: ...irect resets the RETRACT f f sets the CNT 2048 f f and causes the RDY D LY A f f to be reset See Figure 4 19 The Q output of this f f generates the RTZ high signal to the SLB CNT 2000 FF FIDX RETRACT AC OR DC LOSS NOT RDY 5V DC LOSS RUN D o C RE TRACT o D o SPM C ON FF SPM ON SW 010 D TO NAND GATE B C BRUSH MOTOR ON CNT 1980 FF I CNT 2020 FF ___ 0 D RDY DLY A FF FF 0 0 CELL 3 D ot CELL 1 SPINDLE C...

Page 86: ...will set RDY DLY B f f The next FIDX pulse will gate LD HD to the SLB At the same time RDY 1 will be sent to the CIB for processing and eventual gener ation of READY to the Controller after the Initial Seek operation is finished 4 5 3 4 3 SP DETEC The Speed Detect signal when low allows Write operations When it is high it inhibits Write operations on the DEB SP DETEC will be high if the counter de...

Page 87: ...store operation this register will be reset by the Clear Counter CL CNTR signal During a programmed Seek the new cylinder address from the Controller will be routed to th8 SLB on input lines ADD 1 through ADD 256 These inputs are applied to the 100 and 200 TPI multiplexer whose outputs are then strobed into the NAR by the Seek Strobe SK Therefore during contin uous or alternate Seek operations the...

Page 88: ...ODER 0963 001 ILL ADD SK __1 TCV DL Y DT CLCNTR L __ CNT PLS EN i DT P ______ J UNLOAD Ll DL Y SKILl C FWD F F LOAD ___ J r TDAC 9 LINES CAR DT EN i r 256 128 5 LINES D A CONVERTEH SUB 4 SUBTRACTORI1 t_ 1 7 LINES ZERO DECODER D DAC ZERO _4 0DD L _4 FWD L Figure 4 20 Block Diagram of Servo Logic Board SLB 4 29 ...

Page 89: ...lse is developed by the position transducer two tracks before the carriage reaches track 000 position This negative going pulse is developed on the SVA board and is routed to the SLB There the positive transition is used to clear the LOAD f f and to set the DLY BOT f f The Q output of the DLY BOT f f maintains the positive LOAD UN LOAD signal to the SVA board and ensures that forward motion will b...

Page 90: ...56 CAR 256 SUB 3 D T CAR 128 NAR 128 H CAR 64 NAR 64 4 CAR 32 SUB 2 NAR 32 o CAR 16 NAR16 4H I CAR 8 NAR 8 CAR4 l NAR4 CAR 2 SUB l 4 NAR 2 CAR 1 NAR 1 I H Z U Figure 4 21 Subtractor Circuit 200 TPI 4 31 1129 002 DIFF VALUE TO D A CONVERTER DIFF 1 TOSVA ...

Page 91: ...8 NAR 64 NAR32 NAR 8 NAR 16 __t _ NAR 4 NAR 2 a ILL ADD Decoder 200 TPI NAR128 NAR64 NAR32 NAR16 NAR 8 NAR 4 NAR 2 NAR1 b I LL ADD Decoder 100 TPI Figure 4 22 Illegal Address Gating Circuits 4 32 1130 001 1131 001 ...

Page 92: ...the current value in the CAR equals that stored in the NAR a ZE RO signal is generated This signal enables the set input of the Detent f f and this f f wi be clock set when the Delay Detent one shot times out 4 5 4 10 Temperature Compensation Voltage TCV The TCV signal used on the 200 TPI Disk Drive only provides temperature compensation consisting of an analog signal proportional to the ambient t...

Page 93: ...MP TCDAC I POS CHAN 1 DETENT POS CHAN 2 CIRCUITRY DETENT TO ELECTRONIC TACH NETWORK CURRENT FAULT CURRENT DUAL MTR FAULT THRESHOLD DETECTOR DETECTOR RTN I D C LOSS SERVO DETENT MTR I SIGNAL RELAY DRIVER DETECTOR RELAY AGC LED AMPLIFIER DRIVER DETENT ODD PULSE SHAPER POSITION CHANNEL AMPLIFIER AMPLIFIER DETENT EVEN __ INVERTING H INVERTING PULSE SHAPER Figure 4 23 Block Diagram of Servo Amplifier B...

Page 94: ...Velocity signal would then be applied to the Summing Amplifier and the FWD or REV Driver to develop the Servo Amplifier Output signal for carriage positioning 4 5 5 3 Electronic Tachometer Network This network monitors the Position Transducers POS CHANN EL signal The network senses the carriage velocity and generates a voltage that is applied to the same two FET s as the Velocity Ramp Generator si...

Page 95: ... DLY SK ISLB BOARD lJ 1SEC I 62 MSEC t I F APPROX I DET EN SLB BOARD II U I I COARSE SERVO ENABLE SLB BOARD POSITION TP 5 SVA BOARD VELOCITY TP 3 SVA BOARD I I I I f 4 TRACK 63 FOR 100 TPI UNITS TRACK 126 FOR 200 TPI UNITS D A I I CONVE RTE R TP 2 I SVA BOARD 3 MSEC SEEKCOMP I CIB BOARD L _ _ Figure 4 24 New Address Seek Operation Waveforms 4 36 ...

Page 96: ...ansducer is amplified and shaped on th is board before being routed to the SLB 4 5 5 7 Positioning Servo System Head positioning to a desired track is accomplished by means of the Positioner servo system This system a block diagram of which is shown in Figure 4 25 consists of a positioner actuator a velocity servo loop a position servo loop a summing amplifier and a servo amplifier When the spindl...

Page 97: ...ng I O data to and from the external Controller on separate Read and Write channels and provides the necessary Write Protect logic to ensure that data are not erased A block diagram of the DEB showing signal paths and circuit components is shown in Figure 4 26 Refer to the schematic of the Data Electronics board in Volume 2 when following the circuit analysis 4 5 6 2 Disk Head Selection The four c...

Page 98: ...ER BOARD I F F DRIVERS WRITE I CURRENT R W HEAD ADJUST NO 2 I R W HEAD I NO 1 READ DATA 1 r LOW R W HEAD PASS READ DATA 2 FILTER NO O DATA INTERFACE I BOARD WRITE ERASE WRITE CHECK X SERVO AD256 128 LOGIC WRITE CURRENT SWITCHING BOARD I I OCP R DISK WRT PROT SW WRT PROT F DISKWRT PROT SW Figure 4 26 Block Diagram of Data Electronics Board DEB 4 39 ...

Page 99: ... DATA 1 and 2 are square wave pulses which are sent to the DI B for further processing 4 5 6 4 Write Operation The Write data are received from the external Controller on the WR ITE DATA line It is first processed by circuitry on the Data Interface Board then sent to the Write circuits on the Data Electronics Board DEB The WRITE DATA signal toggles the Write f f the true or false outputs of which ...

Page 100: ...essed and the fixed disk is selected B The removable cartridge PROT CART switch is depressed and the removable disk is selected C The SP DETEC input from the Disk Control Board DCB is high and or two or more ReadlWrite heads are selected simultaneously D Write Inhibit from Control Interface Board CIB is low NOTE Combinations of A B C or D can occur simul taneously except A and B Both disks cannot ...

Page 101: ...is received or when the ERASE signal itself is received The erase gap on each side of the data track is used to erase both edges of the written track to improve reliability of the written data See Figure 4 30 The erase current also flows through the Erase Current Detector which monitors the erase current If an erase current problem occurs the Erase Current Detector will activate the WRTIE RASE Cur...

Page 102: ...sed to approximately 30 milliamperes Since recording density increases in proportion to the track number improved bit resolution is obtained if the inside tracks are written with a lower level of Write current The process is performed in the following manner the most significant bit of the new cylinder address is routed to the Data Electronics Board DEB This signal goes high when the head changes ...

Page 103: ...5 7 2 Seek Complete and Ready When Detent Enable DT EN from the SLB goes high it triggers the 3 msec Seek Complete Delay one shot SKC 0 LY O S and enables the D input to the Seek Complete SKC f f When the SKC DLY O S times out the negative transition will clock the SKC f f set The Q output enables the 0 input to the ROY f f and one leg of an AN 0 gate wh ich is presently disabled by the Q output o...

Page 104: ...L T 1 RTZ SEEK o s STROBE I 0 I I I ILL ADD ADD ACK F F P W L l O S rL 0 SKC C F F STR ADD MUX IDX STR MUX SK DLY O S SKINC DLY O S 1 0964 001 SECTOR ADDR COUNT RETURN TO ZERO If I C SKINC F F INCO SK ADD ACK ILL ADD MPLETE SEEK ATTENTION JUMPERS __ OPTIONAL SEEK COMP JLRESET ROY WRT 0 READY INHIBIT DLY ROY TIMER C F F TRIGGER l Figure 4 31 Block Diagram of CIB 4 45 ...

Page 105: ...roller In addition NRZ coded data is converted to double frequency encoded format for writing on the disk or from double frequency enc0ged data back to the original NRZ format after it is read from the disk This function is performed by the Voltage Controlled Oscil lator VCO 4 5 8 2 Edge Discriminator Operation At the point where the Read data first enters the DI B it is essentially a square wave ...

Page 106: ...N I STR CTRS F F CLEAR Q OUTPUT COUNTER TO O CLR CNTRS ______________rl __________________________________________________ ENABLECNTRS LJ J COUNT SECTOR 1_ COUNTER DISK SEL HIGH MULTIPLEXES FIXED DISK SECTORS TO OUTPUT LlNES BASIC UNIT NO JUMPER ON D20 7 TO D20 8 fJ f SAC 1 SECTOR OUTPUT IN BINARY CONFIG J f SAC 2 Figure 4 32 Current Sector Identification CIS 4 47 ...

Page 107: ...tor This input will be compared to the phase lock loop made up of the voltage controlled oscillator and frequency divider circuit Any phase difference will generate a correction voltage to the VCO When the RD GATE signal goes true the enabling RD SYNC A f f will be set on the next pulse from the bidirectional one shot The Q output of the R0 SYNC A f f will start the DATA 1 lock out which will allo...

Page 108: ... aNAL O S VCO VCO DIVIDER ClK VCO DIVIDER L ALPHA CLOCK n n n n n BETA CLOCK Il n n n n n RD DATA A I RD DATA B I 1 1 1 0 1 1 RD DATA n n n n DATA ClK Il n n n n n Figure 4 34 Data Interface and VCO Timing Diagram 4 49 ...

Page 109: ...ell and a flux reversal will occur If a digital 0 is to be recorded no pulse will occur during the bit cell time and no flux reversal will occur until the clock pulse that initiates the next bit cell period 4 5 8 4 Read Operation Complete When the Read operation has been completed the Con troller notifies the Disc Drive The RD EN GATE line drops thus inhibiting further reading fr om the disk At th...

Page 110: ...r it times out The ENABLE input to the VCO will go active and READ DATA will be routed to the DATA SEPARATOR and PHASE DETECTION circuits and cause the VCO to lock to the READ DATA Depending upon jumper option either NRZ or Pulse data will be sent to the Controller also by jumper option adjustment of clock timing within a bit cell time is available 4 5 9 2 Write Operation The Seek Complete SEK COM...

Page 111: ...TA ClK READ SYNC CKTS CROSSOVER DETECTION CKTS READ PHASE OIS 1010 002 READ DATA NRZ DOUBlE FREO rap N L ORK 1 I CAll CLOCK it TIMING L __ WRTClK DATA SEPARATOR CKTS __ ENABlE VCO IVCO ADJ Figure 4 36 Simplified Logic Diagram Read Circuitry 4 52 ...

Page 112: ... ERASE GATE WRITE GATE e ERASE r CLOCK DIVIDER D a C 6 4 BIT MUlTlPlEXER SHIFT REG ENABLE D a C A Q a B a a C a a D Figure 4 37 Simplified Logic Diagram Write Circuitry 4 53 1011 002 9WRT elK TO READ CIRCUITRY ...

Page 113: ...rd to supply drive current to the spindle motor 4 5 11 2 Board Operation Refer to the schematic of the Commutator Board in Volume 2 when following the circuit analysis of spindle drive motor control The three CE LL outputs from the Commutator Board are applied to the Motor Drive Power Switch Board at pins 4 5 and 6 These inputs are routed to an auxilliary output which is required on some Disk Driv...

Page 114: ...he schematic of the circuit board A shutter is attached to the shaft of the spindle motor and rotates with it As the shutter successively cuts off the light flow to two of the interruptor switches and allows the third switch to conduct the three output lines labeled CE LL 1 CE LL 2 and CE LL 3 are activated in turn The output of the acti vated switch is routed through a comparator circuit to the M...

Page 115: ...tracted position A slightly modified version of this PWB is used in 20 megabyte Disk Drives 200 TPI 4400 BPI It provides the same functions except it has a two speed Retract Retract speed on 20 megabyte drives must be kept below 50 ips 127 cm sec during entire Retract or disk damage may occur as heads unload Proper Retract speed is accomplished by a 100 Ohm resistor in series with Retract current ...

Page 116: ... the 3 36 sec retriggerable SPM START O S The out put of the one shot will provide the gating input to the SPM MTR ON NAND gate which will generate the SPN MOTOR ON L drive signal to start the spindle rotating At the same time it will turn on the brush motor turn off the load indicator light and de energize the drawer front panel lock solenoid As the brush motor turns the brush tower will activate...

Page 117: ... de codes from the counter circuits on DCB are used While spindle speed is increasing FI DX pulses are not arriving in time to keep the counters from reaching their maximum count 2048 This will inhibit Write operations not necessary at this time but very useful later and keep the carriage retracted Carriage movement is inhibited by the RTZ signal generated by the Q output of RDY DLY A f f which is...

Page 118: ... operation RTZ would go high The reason for this is speed could diminish to the point that proper head flight would not be maintained and severe damage to heads and disk surfaces could result 4 6 2 2 Head Loading Operation The major portion of this discussion will be in reference to SLB Signals generated in the previous operation which pertain to this one will be discussed in order of their genera...

Page 119: ...FF AFTER LD HD S SS FWD L H q JI S S LOAD UN LOAD BOT DLY BOT FF S CL CNTR H S DET EVEN S l I 1 7 MS DET ODD S I 1 O 4MS 0 45 MS DT EN S S 4 4 MS FROM BOT I LD HD L U St S SS CNT PLS EN 4 4 MS FROM BOT I Figure 4 39 Head Load Timing Diagram 4 60 ...

Page 120: ...signals necessary for carriage motion and keeping the CAR cleared The Qoutput of the DLY BOT f f enables the Detent Odd DET ODD pulses to the clock input of the DTEN f f on SLB Since the ZERO signal Subtractor difference value equals zero to the D input of the DT EN f f is high the next DET ODD pulse will set it The Q output of this f f resets the DLY BOTf f and generates the Detent Enable DT EN s...

Page 121: ...is equal to the NAR value Detenting then takes place and SEEK COMPLETE status signals will be sent to the Controller signaling the drive is ready to perform a Read or Write operation See Figure 4 40 4 6 4 RESTORE OPERATION When a Restore command is received on CI B RTZ O S fires and generates a 12 usec pulse R E TURN TO ZERO This pulse is sent to SLB and sets the UNLD f f The UNLD f f generates FW...

Page 122: ...S r _________ i 35J LS DTP DT EN L CNT PLS EN L FWD REV EN L SK ACCELERATE U CL CNTR DLY DT SAME AS DTP 1 r 40 J LS U U U u SET DT EN FF DLYSK U 1 r 180NS SK COMP J 3 8MS ODD L D DAC 2 CYL MOVE 0 j3V 2 1 MS ____ 0 17V 4 7MS DAC ON 2 CYL MOVE D DAC 1 CYL MOVE DAC ON 1 CYL MOVE Figure 4 40 Programmed Seek 1 and 2 Cylinder Seeks 4 63 ...

Page 123: ...ET EN L DLY UNLOAD L DT EN L BOT L DLY UNLOAD FF CNT FF DET ODD L DLY BOT FF laMS O S lJ lS O S LD HD L LOAD FF r 1 0965 J JI j J I J J J J 1 ______ J L I J L L 1 16MS 1 I __________ I 4JJ IJJI tJJ u u L laMS I __ I JJ lJJ S zu 700NS Figure 4 41 Timing Diagram of Restore Operation 4 64 ...

Page 124: ...he SPEED DET f f will be reset This will generate SPEED DETEC high which will inhibit Write operations because the spindle speed is too fast and data from one sector could be written into the next sector wh ich could destroy previously written data in that sector If both flip flops are set when the FI DX pulse arrives once again SPEED DETEC high will be generated to inhibit ovrite operations becau...

Page 125: ......

Page 126: ...tforward and adjustment and test points are within easy reach when the top cover has been removed Certain replacement procedures necessitate access to the bottom area of the Disk Drive Since in most cases the chassis will be mounted on slides such access is easily accomplished by pulling the unit out of the cabinet as far as required The internal flexible I O signal cable which interconnects the s...

Page 127: ...ragraph 5 3 3 6 months Clean surfaces using alcohol moistened kimwipes Remove ferrous particles if any from chuck and magnet ring through application of masking tape 6 months Clean with an alcohol saturated swab through access hole at the front of the unit see Figure 5 1 6 months 5V 13V 13V 1 year Replace prefilter see Figure 5 15 1 year Inspect replace if necessary 1 year Replace brush assembly 1...

Page 128: ...des instructions for the removal and replacement of major as semblies and adjustment and calibration procedures that can be performed on site 5 3 PREVENTIVE MAINTENANCE In Disk Drive installations preventive maintenance is performed only at infrequent intervals since all moving parts including the recording medium are normally enclosed and are purged contin uously by a clean air system However som...

Page 129: ...as the disk be kept clean Vhen in the flying attitude the heads are separated from the disk surface by only a few microns and because of the high disk speed even small particles adhering to the heads may cause damage to the heads or to the disk surface To inspect the head surfaces for accumulation of dust or oxide particles remove the cartridge and illuminate the head area with a suitable light so...

Page 130: ...itch protrudes from the base and keep it depressed by placing masking tape over it For ST units install a matchbook cover between the pack sensor and switch actuator See Figure 5 2 Insert an alcohol saturated swab through the access hole in the front of the Disk Drive see Figure 5 1 and lightly move it across both the upper and lower surfaces of the disk Repeat this opera tion using a new swab eac...

Page 131: ...DISK CLEANING ACCESS HOLE Figure 5 1 Fixed DiskCleaning Hole Location CARTRIDGE SENSOR Figure 5 2 Cartridge Interlock Switch Actuation ST 5 6 1142 001 1166 001 ...

Page 132: ...trated and described with emphasis on assembly configuration and location The main mechanical differences between the two series of drives are identified Procedures for the removal and replacement of assemblies and related com ponents and adjustment and calibration procedures are presented 5 4 1 GENERAL DESCRIPTION The majority of assemblies and components in the SF and ST Disk Drives are intercha...

Page 133: ...ERFACE BOARD J1 CONTROL INTERFACE BOARD J2 DISK CONTROL BOARD J3 SERVO LOGIC BOARD J4 SERVO AMPLIFIER BOARD J5 OPERATOR CONTROL PANEL I O CONNECTOR BOARD Figure 5 3 SF Disk Drive with Cover Removed 5 8 1005 001 ...

Page 134: ...S DATA INTERFACE BOARD J1 CONTROL INTERFACE BOARD J2 DISK CONTROL BOARD J3 SERVO LOGIC BOARD J4 SERVO AMPLIFIER BOARD OPERATOR CONTROL PANEL MOUNTING SLIDE RAIL Figure 5 4 ST Disk Drive with Cover Removed 5 9 1002 ...

Page 135: ...SH HOME SWITCH PLENUM CHAMBER COMMUTATOR BOARD O 4i ELECTRONICS CRANK DISK CLEANING INTERCONNECT BRUSH CAM BOARD SPINDLE PULLEY o o o o _ BLOWER ACCESS COVER BLOWER PULLEY Figure 5w 5 SF and ST Disk Drives Assembly Identification Bottom View 5 10 1408 001 ...

Page 136: ...REMOVABLE DISK INDEX SECTOR TRANSDUCER Figure 5 6 S CARTRIDGE RECEIVER STATIONARY SLIDE F Disk Dnve 1m S plified Front View 5 11 1 BRUSH ARM BRUSH ASSEMBLY I 1143 001 ...

Page 137: ...FIXED DISk OR INDEX SEC R TRANSDUC SHROUD Figure 5 7 ST S piified Front View Disk Drive 1m 5 12 0248 001 ...

Page 138: ... is closed To release these latches from their locking pins they must be tripped manually a slot is provided in each latch for this purpose The painted front trim panel must be s apped out to gain access to the front part of the latch The latch is depressed and thus released by applying a downward force on the slot in the latch 5 4 1 2 Front Door and Cabinet Lock Series T The ST Disk Drive incorpo...

Page 139: ...nt Service Aids Test Hub XX number of sectors Test Hub XX number of sectors Printed Wiring Board Extender Data Electronics Board Extender Power Regulator Board Extender Power Supply Extender Cable Power Supply Extender Cable replaces 001 Servo Amplifier Board Extender Cable Head Extender Cable adapter for testing Write Current Spindle Phasing Harness Adapter Spindle Phasing Harness for use with Hi...

Page 140: ...nt color Shipping bracket left used if customer does not want cabinet slides Shipping bracket right used if customer does not want cabinet slides AI ignment Cartridges C E Pack 2200 BPI Tri Bit Type C E Pack 2200 BPI Tri Bit Type C E Pack 2200 BPI Cat Eye Type customer request only C E Pack 2200 BPI Cat Eye Type customer request only not for 4400 BPI C E Pack 4400 BPI MFM Type T 2422 Unrecorded Ca...

Page 141: ...rives as described in paragraph 5 3 6a To reinstall the top cover on the SF disk drive insert all six screws loosely to permit slight shifting of the cover for hole alignment Then tighten each of the six screws evenly TO PREVENT DAMAGE TO THE TOP COVER ON THE ST DISK DRIVE THE FOLLOWING HOLE ALIGNMENT PROCEDURE SHOULD BE FOLLOWED To reinstall the top cover on the ST Disk Drive perform the followin...

Page 142: ...SHROUD REMOVE FIXED DISK COVER REMOVE C II SWITCH ACTUATOR FIXED DISK EXPOSED REMOVE FIXED DISK COVER 5 4 2 6 2 FIXED DISK EXPOSED 5 4 2 6 1 I DISK BRUSH MOTOR FIXED DISK DISK BRUSH MOTOR 5 4 2 12 REMOVAL 5 4 2 14 5 4 2 7 I DISK DRIVE THERMISTOR ASSY SPINDLE ASSEMBLY REASSEMBLY 200 TPI ON LY REMOVAL 5 4 2 13 5 4 2 8 5 4 2 9 I OPERATION OF THE FIXED DISK SPINDLE ASSEMBLY DISK DRIVE WITH THE SECTOR ...

Page 143: ...located at the base of the power supply Access is through a hole in the EIB cover and EIB on the bottom of the drive The power supply can now be lifted from the Disk Drive D To replace the power supply install and tighten the screw at the base of the power supply and install the two 20 screws to fasten the power supply to the top edge of the casting Apply silicone grease to the edge before fasteni...

Page 144: ...SUPER SERIES 1355 001 P9 DC FUSES C MOUNTED3 0 REAR PANEL IL ll i AC FUSE Figure 5 10 Power Supply Assembly 5 19 ...

Page 145: ...om of the unit through the three access holes in the EIB cover DO NOT REMOVE THE HEAD LOAD CAMS OR HEAD MOUNTING BLOCK IN THE FIELD UNDER ANY CIRCUMSTANCES DURING REMOVAL OF THE POSITIONER CONTACT BETWEEN THE CARRIAGE FRONT END STOP AND THE FIXED DISK MUST BE AVOIDED DO NOT LIFT THE POSITIONER BY THE HEAD LOAD CAM FOLLOW THE PROCEDURE BE LOW G Lift the positioner slowly off the casting while const...

Page 146: ...SUPER SERIES Assembly 5 11 Positioner Figure 5 21 1390 001 ...

Page 147: ...e retained they should be trans ferred to a scratch cartridge prior to removal of the fixed disk If the disk is to be reused extreme care must be used to ensure that the disk remains clean and does not touch hard surfaces ST Disk Drive The preliminary disassembly leading to the exposure of the fixed disk differs somewhat between the two series of Disk Drives To remove the ST fixedidisk assembly pe...

Page 148: ...nsducer and remove the cover The fixed disk in the ST Disk Drive is now exposed 5 4 2 6 2 SF Disk Drive Prior to removing the fixed disk assembly on the SF Disk Drive per form the following steps 5 4 2 7 A Remove the colored trim panel and the retaining screws on the operator control switch plate by the same procedure as in Step B of paragraph 5 4 2 6 1 B Remove the two 6 32 screws one for each en...

Page 149: ...Lift the belt off the two pulleys at the bottom of the Disk Drive B Remove the three 6 32 screws used to fasten the gasket cover to the spindle and remove the gasket C Remove the air filter access cover loosen the wedge shaped filter clamps and remove the air filter see Figure 5 15 D Disconnect the spindle motor plugs from the Power Switch Board located in the plenum chamber see Figure 5 15 E Remo...

Page 150: ...GROUND BRUSH PLUG MATES WITH MOTOR DRIVE POWER SWITCH RECEPTACLE Figure 5 12 Spindle Assembly 5 25 1145 001 ...

Page 151: ...ly make certain that it is inserted perfectly straight No undue force should be used or necessary when performing this operation B Reconnect the spindle motor plugs Disk Brush Motor Replacement To replace the disk brush motor see to Figure 5 13 and perform the following steps 5 4 2 13 A Extract leads from plugs P11 6 and P11 1 or P11 4 An alternate method is to unsolder the two leads on the motor ...

Page 152: ...ew washers and in stall the 6 32 nuts Tighten the nuts alternately in a criss cross pattern and tighten each nut to 8 inch pounds 20 32cm 0 4536kg with a torque wrench D Reassemble the Disk Drive in a reverse order of its disassembly as previously de scribed Verify that both transducer outputs align the index to data see Table 5 3 for a list of procedures for alignment and adjustment of the DiskDr...

Page 153: ... 3 9 SERIES T 5 4 3 1 I 5 4 3 18 5 4 3 13 I CARTRIDGE REMOVABLE PLUG IN COMMUTATOR IN rERLOCK INDE X SECTOR I O CONNECTOR CIRCUIT BOARD 5 4 3 23 I MOTOR POWER SWITCH BOARD 5 4 3 4 SWITCH TRANSDUCEf BOARD ASSEMBLY SERIES F BOARDS 5 4 3 19 5 4 3 10 5 4 3 12 5 4 3 14 I I SPINDLE SPINDLE ELECTRONICS DOOR LOCK LIMITER GROUND INTERCONNECr SOLENOIDS BOARD BRUSH BOARD 5 4 3 20 54 3 5 54 3 8 5 4 3 15 5 4 3...

Page 154: ...lling the filter element make sure that the arrow label which indicates the direction of air flow on the filter case points toward the outside wall of the casting The prefilter will face the spindle assembly 5 4 3 3 NOTE If the following parts are to be replaced this must be accomplished before reinstalling the filter element 1 Fixed Disk Sector Transducer 2 Motor Drive Power Switch Circuit Board ...

Page 155: ...Figure 5 15 Air Filter Installation 5 30 GASKET 300939 1147 001 ...

Page 156: ...lenum cham ber next to the spindle assembly and is accessible from the air filter cavity If the air filter is in place first remove this component To remove the Motor Drive Power Switch Board unplug all electrical connectors from the board Remove the two 6 32 screws which are available from below the base plate and which are used to mount the heatsink to the casting The board then may be Iifted ou...

Page 157: ...the blower shaft ground brush is to be re placed this should be done prior to reinstalling the blower access cover and the blower pulley Blower Shaft Ground Brush The blower shaft ground brush is mounted in the bearing housing of the blower The brush is to be replaced if the resistance between the blower shaft and the casting exceeds 1 5 Ohms with the shaft rotating To replace the brush remove the...

Page 158: ...tart operating cycle The SF units contain a set of two brushes which are used to sweep the fixed disksurface The ST units contain tw sets one set being used to sweep the fixed disk and one set for the cartridge disk If the brushes are not in good condition bristle tips are not touching they must be replaced See Figure 5 18 for correct mounting of the cleaning brushes 5 33 ...

Page 159: ... SCREW C i T c l am l r J L 1 GROUND I______ BRUSH SPINDLE Figure 5 17 Spindle Shaft Ground Brush Mounting C DISKEDGE CORRECT INSTALLATION 1150 001 I BRUSH REPLACEMENT REQUIRED Figure 5 18 Disk Cleaning Brushes Installation Replacement Guide 5 34 ...

Page 160: ...eying of the brushes in the arm there are two types of brushes a right hand brush and a left hand brush NOTE The brush may be installed only once or its retention capabil ities are greatly decreased Cartridge Interlock Switch This mechanism consists of a microswitch and a plunger type actuator on its upper end When the disk cartridge housing is seated in the Disk Drive the act uator is engaged The...

Page 161: ... the actuator until it clicks which indicates the switch has been actuated Tighten the switch mounting screws while holding the switch securely in the adjusted position NOTE Some small travel should remain in the switch after it has been adjusted i e the actuator plunger should not press the switch mechanism to its stop when the cartridge is seated 5 4 3 11 Disk Brush Home Switch This microswitch ...

Page 162: ...p side of the fixed disk cover To remove the transducer perform the following steps A Remove the two 4 40 screws Note or mark the position of the transducer on the bracket prior to removal This will facilitate index alignment B When reinstalling the transducer line it up to its original position mark as noted in Step A After replacement perform the removable disk Index Sector trans ducer check and...

Page 163: ...n the side of the transducer mounting block Remove the leads from the housing of connector P12 Turn the transducer counterclockwise until it is completely removed from the mount ing block C Install a test hub on the spindle Screw the replacement transducer into the mounting block clockwise rotation until it just touches the sector ring Back off the transducer sl ightly and with the aid of a sh im ...

Page 164: ...tors from the board D After replacement of the circuit boards perform the applicable alignment adjust ment or operational check see para 5 5 1 Electronics Interconnect Board This circuit board mother board incorporates the connecting recl ptacles of all six plug in boards as well as connecting pins for various harness cable connectors see Electronic Interconnect PWB Dwg Volume 2 The Electronics In...

Page 165: ... head assembly READ WRITE HEAD TOP VIEW LOAD RAMP 1154 001 HEAD CONNECTING CABLE Figure 5 22 ReadlWrite Head Assembly Replacement of the head assemblies is simplified if the power supply assembly is temporarily removed from the Disk Drive to obtain unrestricted access to the head area However it is possible to remove the ReadlWrite heads with the power supply in place WHEN REPLACING FIXED DISK HEA...

Page 166: ...HER OBJECT DO NOT BEND THE HEAD BEING REMOVED BEYOND THE CAM HEIGHT TO AVOID DAMAGE TO THE HEAD After replacement of a head assembly perform the following procedures F Data Separator Check see paragraph 5 5 12 G Head Alignment see paragraph 5 5 11 H Index Alignment see paragraph 5 5 9 5 4 3 17 Use of Torque Wrench An inexpensive torque wrench has been developed by the Company which will be useful ...

Page 167: ...o CORRECT 6 5 7 5 IN LBS 15 49 18 03 CM 453 6 G o TORQUE o INCORRECT EXCESS TORQUE WRENCH Figure 5 23 Torque Wrench No T 00425 Application 5 42 0958 001 B ...

Page 168: ...onnect cable assembly 5 4 3 19 I O Connector Board This circuit board is mounted on the rear panel of the Disk Drive It incorporates the input output line connectors and Iine drivers and receivers see Figure 2 5 To remove the I O Connector Board take out the four mounting screws one at each corner used to fasten the circuit board and its cover to the rear panel then lift out the board and its cove...

Page 169: ... to be replaced unsolder the leads and tag each lead to indi cate its polarity as described in step A of paragraph 5 4 3 20 5 4 3 22 Emergency Retract PWB Assembly Th is PWB is located at the rear side of the Disk Drive and is mounted next to the positioner assembly To replace this circuit board see Figure 5 24 and perform the following steps A Disconnect plug P17 and remove the four 4 40 screws u...

Page 170: ...lowing pages procedures are described for all adjustments and calibrations that can be performed at the installation site The procedures are listed in the sequential order to be followed if a complete calibration covering every item described should be intended All test equipment specified in the procedures is listed in subparagraph 5 4 1 3 It is recommended that the subpclragraph 5 4 3 14 describ...

Page 171: ...ives only 5 5 13 5 5 2 POWER SUPPLY ADJUSTMENT To check DC operating voltages perform the following steps A Place the POWER switch in OFF position B Remove the Data Electronics Board from location J7 and insert an extender board in its place Insert the DEB in the extender board C Apply power and monitor the 5VDC at pin D of connector J7 Adjust R 10 on the 5V regulator see Figure 5 3 for exactly 5 ...

Page 172: ... capacitor C5 The spindle should rotate and lock in position EEl DO NOT HOLD CONTACT PIN LONGER THAN 3 SECONDS E Ensure that the spindle does not move while adjusting the interrupter cup as shown in Figure 5 26 F Hold the interrupter cup with one hand and tighten the pulley screws to 24 inch pounds of torque G Rotate the spindle shaft approximately 45 degrees and repeat step D Ensure that the phas...

Page 173: ...SUPER SERIES 11568 HOT J37 P37 LEAD 18V c fr 7 SPINDLE MOTOR ALLIGATORr CLIP PHASING HARNESS Figure 5 25 Power Supply Connections Commutator Board Phasing Adjustment 5 48 ...

Page 174: ...aph 5 4 3 13 E Place the POWE R switch to ON position F Manually actuate the cartridge interlock switch G Place the RUN LOAD switch in RUN position and allow the spindle to reach operational speed H The waveform at pin M of the extender card should have minimum output of 300 mill ivolts base to peak with a maximum overshoot baseline noise of 50 millivolts as shown in Figure 5 27 I If an output hav...

Page 175: ...se to peak with a maximum overshoot of 5 0 millivolts The same pro cedures as those previously described are used to obtain these outputs At no time may the transducer be placed closer than D DD5 inch 0 127 mm from the hub L Overshoot sornetimes may be caused by a metal chip on the pole tip A piece of masking tape can be used to remove the magnetized metal chip M The 1 volt minimum requirement for...

Page 176: ...tion remove the test equipment replace the DCB in card cage location J3 and plug in connector P15 X Perform the Index to data alignment outlined in paragraph 5 5 9 Fixed Disk Index Sector Transducer Adjustment SF and ST In both series of Disk Drives the index sector transducer is mounted in the plenum chamber next to the air filter see paragraph 5 4 3 3 If air filter has not been removed remove it...

Page 177: ...C14 for a reference I If the amplitude of the output waveform does not have the specified minimum value turn the transducer clockwise very gradually while observing the display on the oscilloscope until the amplitude of the signal is within limits J Place the POWE R switch in OF F position and carefully tighten the jamb nut onthe transducer assembly Verify that the position of the transducer has n...

Page 178: ...the POWER switch then press the RUN portion of the RUN LOAD switch and allow the spindle to come up to operational speed G Place the oscilloscope vertical probe at the input to the differentiator circuit pin M of circuit board connector J3 The signal should appear as shown in Figure 5 29 H If the waveform at the input to the differentiator circuit is not approximately as shown in Figure 5 29 check...

Page 179: ... 5 5 5 SVA ADJUSTMENT PROCEDURES NOTE This procedure is only to be used for SVA boards with revision letter D or above THESE PROCEDURES ARE DESIGNED TO BE ACCOMPLISHED IN SEQUENCE HOW EVER IF MAINTENANCE PERSONNEL DEEM IT NECESSARY TO PERFORM IN DIVIDUAL CHECKS OR ADJUSTMENTS WITHIN THESE PROCEDURES THE FOL LOWING MUST BE OBSERVED A Check initial procedure conditions i e POWER ON OFF JUMPERS insta...

Page 180: ...ack into J3 D Connect a scope probe to Detent signal test point H63 on the SVA Select internal sync and vertical sensitivity of 2V cm and install a cartridge or test hUb E Place the POWER ON OFF switch to ON and the RUN LOAD switch to RUN F When the disc has reached full speed manually load the heads G While manually moving the positioner carriage back and forth adjust the AMPLITUDE potentiometer ...

Page 181: ...ecessary only when replacing Detent assembly D Check amplitude of BOT Analog pulse Amplitude must be at least 4 5V includ ing maximum offset voltage of 2 0V when Detent signal amplitude is 12V p p E Check and adjust phasing between BOT Analog pulse and Detent signal Move CHAN 2 scope probe from TP B27 to TP B15 and set scope to trigger on positive going edge of BOT pulse at TP B15 F Manually move ...

Page 182: ...ep H OV DETENTTP 4 5V BOT ANALOG OV BOT PULSE BASELINE DETENT SIGNAL I I I ov I I I I DETENT SIGNAL PREFERRED LOCATION W BOT I Il I 6 IL tA iREA OF ACCEPTABLE BOT POSITIVE GOING EDGE Figure 5 31 Phasing Adjustment Waveform 5 57 1455 001 ...

Page 183: ...POSITIONER CARRIAGE INNER BLOCK MOUNTING SCREWS Figure 5 32 Optical Detent Assembly Phasing Adjustment 5 58 1093 2 002 ...

Page 184: ...e operations To align the servo electronics perform the following steps A Place the POWER ON OFF switch to OFF B Disconnect plug P15 from the SVA board in card cage location J5 remove the SVA board insert a card extender in its place and insert the SVA in the card extender C Review paragraphs 5 5 5 1 and 5 5 5 2 and perform any adjustments needed Remove any temperature compensation or offset jumpe...

Page 185: ... DC OFFSET potentiometer E 19 until the overshoot after seek com plete see CAUTION following step I on adjacent odd and even tracks is symmet rical around OV see Figure 5 33 and 5 34 I Verify that the overshoot at or after seek complete is 0 3V max Careful adjustment of the Injection Velocity potentiometer H61 from the setting arrived at in step G will modify the overshoot waveform Before attempti...

Page 186: ...RESPONSE MAXIMIZES RELIABILITY Figure 5 33 100 TPI Drive Detent Waveform Alternate One Track Seek 1071 CHAN 1 ON TPH63 DETENT SIGNAL CHAN 1 ON TPH63 DETENT SIGNAL CHAN 2 ON TPH65 SEEK COMPLETE EXERCISER CHAN 2 ON TPH65 SEEK COMPLETE EXERCISER INCORRECT ADJUSTMENT OVERDAMPED RESPONSE CORRECT ADJUSTMENT SLIGHTLY UNDER WILL CAUSE POWER AMP TO OVERHEAT DAMPED RESPONSE MAXIMIZES RELIABILITY Figure 5 34...

Page 187: ...e Channel 1 probe to the Detent signal test point H63 with a sweep rate of two 2 milliseconds per division and channel 2 probe on the Seek Complete test point H65 Sync externally on Seek Complete at test point H65 This will give a superimposed representation of the alternate forward and reverse detent signals Adjust the balance potentiometer E 18 to equalize the last positive and negative peaks to...

Page 188: ...iation and flatness of the detent waveform is within 0 6V as shown in Figure 5 37 The waveforms see Figure 5 37 represent some common optical detent assembly waveforms associated with scale flatness Out of flat waveforms must meet the specified maximum variation of 0 6V on either or both sides C Repeat all steps of paragraphs 5 5 5 2 5 5 5 3 and 5 5 5 4 until no further ad justment is necessary St...

Page 189: ...DETAI L 8 Figure 5 35 Fine Offset Adjustments NORMAL WAVEFORMS A B T VARIATION OF 8 PORTION 0 O IV VARIATION OF A PORTION C s O SV C T 12908 VARIATION OF A O 6V VARIATION OF B O 6V t A av av f H 4 H I U U H I J T H T f H t t H H f H f H H I H R to i TYPICAL OUT OF FLAT WAVEFORMS Figure 5 36 Detent Signal Output Waveforms 5 64 1 j ...

Page 190: ...n the Detent mode measure the voltage at LED DRIVER test point 017 It must be 4 0V or less This verifies that the LED current is 80 Ma or less Current Fault Circuit Use the following procedure A To verify the operation of the Current Fault Detector command a seek to approximately the middle of the disk B With the drive in Detent Mode apply a smooth firm pressure on the carriage in unload direction...

Page 191: ...A Place the POWER ON OFF switch to OFF B Disconnect plug P15 from the SVA board remove the SVA board from card cage location J5 insert a card extender in its place and insert the SVA board in the card extender Remove temperature compensation jumpers A43 to A44 and B40 to B44 C Connect plug P15 to the SVA using the cable extender PN 300789 001 D Place the POWER ON OFF switch to ON and LOAD RUN swit...

Page 192: ...eplace SVA and power up the Drive I Command an incrementing one track seek and observe with a scope the base line shift on Detent signal test point H63 The vohage level shift at track 400 should be equal in amplitude and opposite in polarity from track 000 J Adjacent even and odd tracks should have essentially equal amplitudes and opposite polarities The base line can shift as much as 0 5V at extr...

Page 193: ... 097 THIS DATA PERTAINS TO 16 60 8 15 000 34 93 2 6 807 THERMISTOR 17 62 6 14 320 35 95 0 6 530 PART NO 101193 5 5 8 READY INHIBIT CHECK To check Ready Inhibit use the following procedure A Place POWER ON OFF switch to OFF Remove P15 from SVA board remove SVA board from card cage location J5 insert a card extender into J5 and place SVA in extender Connect P15 to SVA using cable extender PN 300789 ...

Page 194: ...ack 005 for the ST 100 TP I drives 190 on SF and 010 on ST for 200 TPI drives H Adjust the INDEX ALIGN potentiometer B95 on the DCB in card cage location J3 to obtain the specified time relationship for the appropriate waveform as shown in Figure 5 38 Ensure that the oscilloscope is begin triggered on the lead ing edge of the Index pulse I Select the other Read Write R W head and verify that the o...

Page 195: ... Index pulse either the transducer or the DeB components should be investigated M After completion of the index alignment remove power from the Disk Drive and take out the CE Cartridge N On ST Drives reset switches on DeB to original position if they were changed see label on front of drive behind trim panel 1170 I III I II J r j II ijij If11 Figure 5 38 Index to Data Alignment 2400 rpm shown 5 70...

Page 196: ...onnect the Write Current Adapter PN 101183 to J24 H Connect the head cable to the Write Current Adapter I Connect the oscilloscope channel 1 input probe from channel 1 to the wire loop on the Write Current Adapter J Press the POWER switch then place the RUN LOAD switch in RUN position and allow the spindle to come up to normal operational speed K Check for a peak to peak waveform of 34 to 36 rnA w...

Page 197: ...1171 f n tr I jJ Jj Figure 5 39 Write Current Waveform Track 000 1172 I I I I J jU I V Figure 5 40 Write Current Waveform Innermost Track 5 72 ...

Page 198: ...nly verification of head alignment is intended perform steps E through J and select first the lower head of the pair then the upper while observing waveforms then perform steps P and Q For head alignment perform entire procedure A Place POWE R switch to OF F position For ST drives see DCB switch setting chart on front of drive behind trim panel If cartridge has only one notch on sector ring set fo...

Page 199: ...T APPROACHING TRACK 4 APPROACHING TRACK T A j if 1 1 ON TRACK LOOPS EQUAL LENGTH EACH LOOP y ROTATIONAL TIME ON TRACK J I IJ UU l 1095 OVERSHOT TRACK OVERSHOT TRACK J l I r V r Figure 5 41 Read Write Head Alignment Waveforms Removable Disk 5 74 ...

Page 200: ... the cartridge disk pair Check whether or not Head and or Disk Select inverted options have been incorporated If so this should be taken into consideration when checking output waveforms L Turn the adjustment screw for the lower R W head clockwise until the correct waveform is obtained see Figure 5 41a M Select the upper R W head of the cartridge disk pair and turn the adjustment screw clockwise u...

Page 201: ...TIONS A Trigger the scope internal source channel 1 EEEl TRIGGER MUST NOT BE ON INDEX OR ONLY ONE SEGMENT OF THE TRACK WI LL BE ALIGNED B Set vertical sensitivity to 50 mV cm and sweep to 2 usec cm C Place CHAN 1 scope probe on R W head test point C30 or B27 on the DEB and adjust heads per paragraph 5 5 11 3 excluding scope setting instructions Adjust for minimum difference in length between adjac...

Page 202: ...s to be recovered the head position will be changed as described in the following steps until data on the fixed disk can be read ac curately This procedure may be performed On Line G If Controller is not to be used install an Exerciser H Place POWE R switch to ON position Install a scratch cartridge Place RUN LOAD switch to RUN I Connect CHAN 1 scope probe to R W head test point C30 or B27 on the ...

Page 203: ...is check Press the RUN LOAD switch to F Select the upper head on the removable cartridge and write an all zeros pattern at track 000 G Connect Channel 1 of the oscilloscope to pin 5 of the IC at location C25 and Channel 2 to pin 4 Sync internal positive from Channel 1 H Set the leading edge at the Channel 1 signal on the zero time base reference line I Monitor the time interval from the leading ed...

Page 204: ...procedure a Remove power from disk drive Install extender card in connector J1 of card cage and mount MFM in this extender card b load a scratch removable disk cartridge in disk drive c Connect disk exerciser to disk drive then power up disk drive d Write an all zeros pattern on track 405 then stop disk exerciser e Use internal sync on oscilloscope connect channel 1 oscilloscope probe to elK DIVID...

Page 205: ...t the RD PHASE one shot should time out between 100 and 180 nanoseconds as shown in Figure 5 43C m Connect one oscilloscope probe to DATA SEPARATOR one shot test point zone 855 and connect other oscilloscope probe to VCO RD DATA flip flop test point zone 856 Sync positive with sync probe on test point at zone B56 and observe th ree cycles n Adjust DATA SEPARATOR ADJ potentiometer zone 058 for timi...

Page 206: ... on B56 VCO 2 The positive transitions of B55 should be occurring in the center of a positive pedestal of B56 for a logic 1 and in the center of a negative pedestal of 856 for a logic zero G Power down the Disk Drive and disconnect all test equipment The adjustment and alignment procedures are complete NOTE To accomplish error checking with an Exerciser it is necessary to have the optional Cell Cl...

Page 207: ... way E Power down the Disk Drive and disconnect all test equipment Adjustment and Alignment procedures are complete WRT DATA E231 J 00 NSEC H H J ____ WRT ClK C54 I J L MIN 20 NSEC I Figure 5 45 Write Clock to Data Timing Adjustment 1051 20 Megabyte Emergency Retract Check To make this check perform the following A Position heads to track 400 B Trigger scope on Retract f f DCB E50 5 C Place chan 1...

Page 208: ...s D Place scope probe on 050 pin 5 SKC DLY O S and adjust potentiometer C31 for 4 msec 5 E Power down drive reinstall CI B and disconnect scope This completes adjustment of CI B 5 6 TROUBLESHOOTING Use the fault isolation chart in Table 5 6 as an aid in identifying locating and correcting possible malfunctions of the more common type The last remedy column specifies the applicable com ponent or ci...

Page 209: ...en POWER switch is turned on Cable from EIB loose Reseat connector P8 5V DC absent Check 5V DC fuse F3 13V 13V inputs Replace regulator chips G40 absent G30 on DEB Defective component on Replace Disk Control Board Disk Control Board Brush sWitch S6 defective Replace brush switch S6 3 Handle does not un Solenoid plunger caught Readjust door latch mechanism lock when unit is on latch powered up Defe...

Page 210: ...kage NOTE Ready light will Belt may be broken Replace OH Ring belt not illuminate until If heads do not load spindle Check 13V DC and 13V DC cartridge temperature is stabilized on 200 TPI may not have come up to outputs on DEB units speed Lack of input to Disk Verify that transducer is plugged Control Board into connector P12 on Elect ronics Interconnect Board and that output is normal If so check...

Page 211: ...may be indicator may be following isolated by observing the a valid or invalid indication characteristics of these signals such as and the generated outputs on 1 Low spindle speed DCB If abnormal replace 2 Current sense DCB 3 AC loss 4 DC loss 8 Disk Drive will not Interface cable or line Reseat connector or terminator I respond to externaI terminator may be loose at assembly on I O Connector posi...

Page 212: ... Head alignment off Realign Index to data off Realign Data Timing inaccurate Replace DIB Fixed disk transducer mis Perform fixed disk index adjusted or defective if sector transducer adjustment errors on fixed disk only or replace transducer Defective component in Replace DEB Check Write analog read data chain current Defective component in Replace DEB and perform digital read data chain data sepa...

Page 213: ...ssing not go out RUN LOAD place RUN LOAD switch and the LOAD portion of switch defective or Disk replace DCB RUN LOAD Control Board is defective If READY indicator goes Bend switch arm to alIow it out home switch 57 is to swing freely or replace defective or misadjusted switch 57 If READY indicator goes Replace DCB 5LB or SVA out bad DCB SLB or SVA board 12 LOAD indicator will Defective component ...

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Perkin-Elmer SF Series, Operation And Maintenance

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