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HP5501B 

Service 

 

8-44 

8-146. Power Amplifier Troubleshooting 

8-147.  The heart of the power amplifier is A3U20, a fixed-frequency pulse-width-modulator control unit. 

The IC operates at a fixed frequency set by A3R63 and C38. The outputs are used to control the 

amount of ±1SV current supplied to the laser assembly during the warmup and optical modes of 
operation. To troubleshoot the power amp, theory of operation, schematics diagrams and 
waveforms, and the following procedure have been provided. 

a.

 

Set HTR OK jumper to HI, ~REF ON to La and wait for READY LED to stay on. Set 

POWER AMP jumper to UP. Remove HEATER jumper. Is voltage at U13 (Pin 3) 
approximately 0.1V? If not, check A3R27, R31, R49, R50, R51, C18, and U13. If so, go to 
step b. 

b.

 

Within 1 minute of setting POWER AMP to UP, is voltage at A3TP11 a nonsymmetrical 
square wave with ±peak voltages >13 Volts? (See 

Figure 

8-20.) If yes, go to step d. If 

not, go to step c. 

NOTE 

Figure 8-20 oscilloscope settings are as follows: 
Time/Division: 10 microseconds/division  
Volts/Division: 5 Volts/division  

Coupling: DC 

 

Figure 8-20. Test Point 11 Waveform (HEATER SENSE) 

 

c.

 

Is U13 (Pin 6) > +13 Vdc? If yes, go to step j. If no, check feedback path through R6SB, 
C20, and R32, or replace U13. 

d.

 

Set POWER AMP jumper to DWN. Is voltage at A3TP11 <0.6 Vdc within 1 minute? If yes, 
go to step g. If no, go to step e. 

Summary of Contents for 5501B

Page 1: ...is documentation Copyright Notice This documentation is Copyright 1980 Hewlett Packard and Copyright 2006 Jack Hudler hpdocs hudler org Permission to use and redistribute this documentation for non commercial and internal corporate purposes is hereby granted free of charge Any redistribution of this documentation or its derivates must include this copyright notice You may not sell this documentati...

Page 2: ...ii ...

Page 3: ... number serial prefixes are covered in Section 7 while higher number serial prefixes are documented with Manual Changes Supplements described in Section 7 HEWLETT PACKARD COMPANY 1986 5301 Stevens Creek Blvd Santa Clara CA 95051 7299 Portions by Jack Hudler 2006 hpdocs hudler org MANUAL PART NUMBER 05501 90035 Microfiche Part Number 05501 90036 Printed SEPTEMBER 1986 ...

Page 4: ...perative and be secured against any unintended operation If this instrument is to be energized via an autotransformer for voltage reduction you must make sure the common terminal is connected to the neutral earthed pole of the power source Servicing instructions are for use by service trained personnel only To avoid dangerous electric shock do not perform any servicing unless qualified to do so Ad...

Page 5: ...iii LASER HEAD SAFETY LABELS ...

Page 6: ...enter for Devices and Radiological Health regulations 21 CFR 1040 10 and 1040 11 These regulations may also apply to the end product into which the 5501B will be designed Care must be taken to insure that the end product complies with all applicable national and local laser safety regulations ...

Page 7: ...derations 2 7 2 25 Power Supply Requirements 2 7 2 27 Power Dissipation 2 7 2 29 Fusing 2 7 2 31 Dimensions 2 8 2 33 Mounting and Fixturing 2 9 3 OPERATION 3 10 3 1 Introduction 3 10 3 4 Power Application 3 10 3 6 HP5501B Laser Head Front Panel Controls 3 10 3 8 HP5501B LASER HEAD REAR PANEL INDICATORS AND CONNECTORS 3 11 3 10 OPERATING MODES 3 13 3 12 Warmup Time Operating Notes 3 14 3 13 HP 1074...

Page 8: ... and After Service Product Safety Checks 8 5 8 18 LASER HEAD BLOCK DIAGRAM DESCRIPTION 8 5 8 26 Laser Tuning 8 7 8 29 Warmup Mode Tuning 8 7 8 34 Optical Mode Tuning 8 9 8 40 Laser Assembly Optics 8 12 8 42 Reference Receiver 8 12 8 44 Shutter Mechanism 8 12 8 46 ASSEMBLY SCHEMATIC LOCATIONS OF HP5501B BLOCK DIAGRAM ELEMENTS 8 12 8 47 REAR PANEL LED INDICATORS 8 12 8 52 ASSEMBLY REMOVAL INSTRUCTIO...

Page 9: ... Power Ⓒ 8 36 8 131 A4 Sampler Board 8 36 8 133 A3 CONTROLLER REFERENCE BOARD TROUBLESHOOTING 8 37 8 135 Standard Troubleshooting Procedures 8 37 8 137 Digital Troubleshooting 8 38 8 140 Photodiode and Amplifier Troubleshooting 8 41 8 142 Liquid Crystal Troubleshooting 8 42 8 144 Subtracting Sample and Hold Troubleshooting 8 42 8 146 Power Amplifier Troubleshooting 8 44 8 148 Warm Up Error Amplifi...

Page 10: ...ing Optical Mode 8 9 Figure 8 7 A6 Sampler Assembly Exploded View 8 10 Figure 8 8 Liquid Crystal Timing Diagram Optical Mode 8 11 Figure 8 9 Logic Clip Monitoring of Test IC U9 8 14 Figure 8 10 HP5501B Front Panel and Side Cover Removal 8 16 Figure 8 11 Factory adjusted Sampler Mount MP1 8 18 Figure 8 12 Laser Tube Tuning Characteristics 8 19 Figure 8 13 Quick Tuning Check Test Setup 8 20 Figure 8...

Page 11: ...Assemblies 6 1 Table 6 2 Reference Designations and Abbreviations 6 3 Table 6 3 HP5501B Board Assemblies Replaceable Parts 6 4 Table 6 3 HP5501B Board Assemblies Replaceable Parts Continued 6 5 Table 6 3 HP5501B Board Assemblies Replaceable Parts Continued 6 6 Table 6 3 HP5501B Board Assemblies Replaceable Parts Continued 6 7 Table 6 3 HP5501B Board Assemblies Replaceable Parts Continued 6 8 Table...

Page 12: ......

Page 13: ...HP5501B Installation 1 1 Figure 1 1 HP5501B Laser Head ...

Page 14: ...o components have light frequencies of F1 and F2 The higher frequency component F2 is oriented parallel to the laser base while the lower frequency component F1 is perpendicular to the laser base An optical receiver inside the HP5501B detects the 1 8 MHz frequency difference and places it at the rear panel REFERENCE SIGNAL connector as a balanced output called the REFerence Frequency The reference...

Page 15: ... Schematics and Component Locations 1 10 Instruments covered by this manual 1 11 Attached to each instrument is a serial plate The serial number is in the form OOOOAOOOOO It is in two parts the first four digits and the letter are the serial number prefix and the last five digits are the suffix The prefix is the same for all identical instruments it changes only when a change is made to the instru...

Page 16: ...ion A safety summary is included on the page following the title page 1 16 Equipment Supplied 1 17 The HP5501B Laser Head is supplied with a test polarizer and two 4 pin connectors for use in fabricating the power and reference cables The HP Part Numbers for the three items are Test Polarizer 1000 0616 Reference Signal Connector P1 1251 3450 Power Connector P2 1251 3447 1 18 Available Accessories ...

Page 17: ...o be protected from temperature extremes that could cause condensation within the instrument Relative Humidity Operating 0 to 95 Non condensing Vacuum Wavelength Nominal 632 991372 nanometers Vacuum Wavelength Accuracy 1 X 10 7 Vacuum Wavelength Stability 2 X 10 8 typical Beam Diameter 6 mm typical Maximum Beam Power Output 1 milliwatt Minimum Beam Power Output 120 microwatts Warm Up Time less tha...

Page 18: ...0A if available Laser Power Meter T Range 1 microwatt to 1 milliwatt Accuracy 10 United Detector Technology Model 351L Clip on Milliammeter T A 10 ma range accuracy 0 1 ma HP 428B Logic Pulser T TTL level HP 546A Current Tracer T Sensitivity 1 ma to 1 amp HP 547A Logic Clip T TTL Compatible 16 pin IC mounting HP 548A Logic Probe T TTL CMOS Capability with Pulse HP 545A Digital Voltmeter T DC Volts...

Page 19: ...he instrument has been checked mechanically and electrically Procedures for checking electrical performance are given in Section 4 If the contents are incomplete if there is mechanical damage or defect or if the instrument or some component fails the performance tests notify the nearest Hewlett Packard office If the shipping container is damaged or the cushioning material shows signs of stress not...

Page 20: ...g indicating the type of service required return address and model number d Wrap the equipment in heavy paper or plastic e Use a strong shipping container A double wall carton made of 350 pound test material is adequate f Use enough shock absorbing material three to four inch layer around all sides of the equipment to provide a firm cushion and prevent movement inside the container g Seal the ship...

Page 21: ...HP5501B Installation 2 3 10778B LENGTH 10 METRES 32 8 FT Figure 2 1 HP 10778B Power Cable ...

Page 22: ...HP5501B Installation 2 4 10779B LENGTH 10 METRES 32 8 FT Figure 2 2 HP 10779B Reference Cable ...

Page 23: ... System Interconnections 2 21 Cable Fabrication 2 22 Power and signal interconnecting cables of suitable length may be fabricated using the two plugs included with the laser head Figures 2 4 and 2 5 illustrate the physical details of the two plugs supplied and give part numbers for both the plugs and the recommended cables Refer to Table 2 1 for rear panel connector pin numbers of all available po...

Page 24: ...nce in frequency between laser beam components F1 and F2 Accessory Equipment A1J5 A 15V External 15V Power Input Ext Pwr Sup A1J5 B 15V External 15V Power Input Ext Pwr Sup A1J5 C 5V 5V power test point Accessory Equipment test use only A1J5 D GND Power Ground Ext Pwr Sup REF AND REF OUTPUTS ARE CAPABLE OF DRIVING ONLY ONE UNIT NOTE THE RUBBER COLLAR WHICH GOES OVER THE CABLES IS A VERY TIGHT FIT ...

Page 25: ... Head Note that other components of the system also use 15 Volts Add these to the laser head current requirements to obtain the overall system requirements Table 2 2 HP 5501B Power Supply Requirements Supply Voltage Tolerance Current Requirement 15 Volts 0 3 Volts 0 8 Amperes 3 5 Amperes peak surge for approximately 2 milliseconds at power up 15 Volts 0 3 Volts 0 7 Amperes Other Power Supply Requi...

Page 26: ...HP5501B Installation 2 8 2 31 Dimensions 2 32 Figure 2 6 shows the HP5501B Laser Head dimensions DIMENSIONS IN MILLIMETERS Figure 2 6 Mounting Details and Physical Characteristics ...

Page 27: ...sures are used and the ambient temperature is changed by several degrees centigrade by the HP5501B thermal equilibrium is not established as quickly and the laser should be run for a longer period of time 2 37 Mounting Mount the laser head by means of the three slotted tabs that extend outward from the bottom edges of the unit refer to Figure 2 1 for exact locations and dimensions The mounting tab...

Page 28: ...the rear panel POWER connector A1J5 Ensure that the power source is adjusted to conform to the following requirements before connecting it to the HP5501B Measured Voltage 15V 0 3 Vdc 15V 0 3 Vdc NOTE REPETITIVE POWER UP CYCLING SHOULD BE AVOIDED THIS WILL REDUCE THE EXPECTED LIFE OF THE HIGH VOLTAGE COMPONENTS 3 6 HP5501B Laser Head Front Panel Controls 3 7 Figure 3 1 identifies and describes each...

Page 29: ...egative supply remains at 15 Volts When the positive supply measures 15 Volts and the negative supply is 14 Volts or less negative 3 15V SUPPLY UNBALANCE RED LED LED lights if the 15V input voltages are unbalanced in the negative direction by one Volt or more For example When the negative supply measures 16 Volts or more negative and the positive supply remains at 15 Volts When the negative supply...

Page 30: ...oint the READY LED begins to flash and continues to do so until the laser head reaches operating temperature When the laser head is ready for use the READY LED stays on steady i e Laser has achieved lock and is now generating a stable reference signal 9 LASER ON AMBER LED LED lights to indicate that the high voltage power supply HVPS is on and that laser light is being emitted 10 POWER CONNECTOR A...

Page 31: ...ser is ready to use optical mode Table 3 1 Proper 55018 Rear Panel LED Power up Sequence OPERATING MODES WARMUP OPTICAL PREHEAT HEATER QUALIFIED LOCKING LOCKED LED s 3 6 Min 100 sec 50 sec Continuous use 15V SUPPLY UNBALANCE Red LED OFF OFF OFF OFF 15V SUPPLY UNBALANCE Red LED OFF OFF OFF OFF 15V FUSE OPEN Red LED OFF OFF OFF OFF 15V FUSE OPEN Red LED OFF OFF OFF OFF 15V POWER ON Green LED ON ON O...

Page 32: ...EF will have their REFERENCE LED lit during the laser head warmup period This is due to inversion in the replication circuitry Note that this does not apply to multiple HP10764A B C card installations The MEASUREMENT LED will momentarily light several times during the laser head warmup period provided that the HP10780A Receiver is aligned properly with the beam This occurs because the laser period...

Page 33: ...0745A asserts SRQ The STATUS BYTE of the HP10745A can be read to determine the source of SRQ I n the STATUS BYTE bit 0 corresponds to the REFERENCE ERROR BIT 3 19 Program Modifications 3 20 To monitor warmup time the following program modifications can be added to the example programs contained in Tables 4 12 and 4 13 of the HP5501A Laser Transducer Operating and Service Manual HP Part Number 0550...

Page 34: ...CE ERROR BIT must be false laser ready 42 rds 709 B Read 10745A STATUS BYTE to verify that it is asserting SRQ 43 if B 64 gto bus error If 10745A not asserting SRQ alert operator 44 B 112 B 45 if B 8 B 8 B Isolate REFERENCE ERROR BIT 46 if 8 4 B 4 B 47 if B 2 B 2 B 48 if B 1 dsp LASER NOT READY If true 5517A not READY 49 if B 1 gto 11 Try again 50 gsb check Otherwise use subroutine check to identi...

Page 35: ...o host computer 68 rdb 2 B if B 0 65536 B B Read first word 69 if B 61440 ret If 4 MSB s are clear 5517A is READY 70 int B 256 240 B 15 B B Otherwise isolate REFERENCE ERROR BIT 71 if B 8 B8 B 72 if B 4 B4 B 73 if B 2 dsp LASER NOT READY 74 if B 2 sto 8 If REFERENCE ERROR BIT true try again 75 wtb 2 1 130 3 Abort transfer and setup new transfer in order to read first word again 76 rdb 2 B if B 0 6...

Page 36: ... B 4 prt VOL OUT OF RANGE B 4 B 0 D 21 if B 2 prt MEAS ERROR B 2 B 0 D 22 if B 1 prt REF ERROR 0 D 23 if D 2 ret 24 if A 0 prt X AXIS ERROR 25 if A 1 prt Y AXIS ERROR 26 dsp GO TO GAGE stp 27 gto 0 28 ovf B 8 B 1 D 29 if A 0 X 2 28 10 X 30 if A 1 Y 2 28 Y 31 ret 32 warmup clr 7 rem 7 33 wrt 709 0O0X 34 wrt 709 1X2X30 35 if rds 7 128 ret 36 rds 709 B 37 if B 64 gto bus error 38 B 112 B 39 if B 8 B ...

Page 37: ...wrt 1 r3 160 r4 160 C 31 if abs X r3 r1 1 158 C and abs Y r4 r2 1 158 C gto newdest 32 gto newsample 33 in rdb 2 B if B 0 65536 B B 34 if B 61440 gto er 35 rdb 2 G if G 0 65536 G G 36 int B 14096 D 37 B 4096 D B 38 65536 B G tn 2 D B ret 39 cnv A 1 1 58248e 4 C 160 A ret 40 out wtb 2 4 41 int A 165536 B if B 32767 B 65536 B 42 wtb 2 B 43 A 65536 intCR 165536 B if B 32767 B 65536 B 44 wtb 2 B 45 re...

Page 38: ...4 dsp GO TO GAGE stp 65 gto 0 66 warmup wtb 2 0 0 0 67 wtb 2 1 130 3 68 rdb 2 B if B 0 65536 E B 69 if B 61440 ret 70 int B 256 240 B 15 B B 71 if B S B S B 72 if B 4 B 4 B 73 if B 2 dsp LASER NOT READY 74 if B 2 gto S 75 wtb 2 1 130 3 76 rdb 2 B if B 0 65536 B B 77 gsb er 78 ret 79 end ...

Page 39: ...or the recommended model s 4 5 TEST RECORD 4 6 Results of the performance test may be tabulated on the test record at the end of these procedures 4 7 HP5501B PERFORMANCE TEST 4 8 The HP5501B performance test consists of measuring the HP5501B input voltages and laser power output 4 9 Input Voltage Check 4 10 Check the HP5501B voltages in the following manner Disconnect the POWER cable Measure the v...

Page 40: ... assembly to its open aperture position c Turn the 15 Volt power supply on and wait until the READY indicator is on not blinking This should occur less than 10 minutes after power is applied d Using the Laser Power Meter align the power meter detector for maximum reading NOTE Laser beam must fall totally within the active region of the power meter s detector e If the laser power output is less tha...

Page 41: ...ORMED BY SERVICETRAINED PERSONNEL NOTE The High Voltage Power Supply A2 is disconnected automatically by A1S1 when the HP5501B covers are removed For Adjustments and Servicing purposes the High Voltage Supply can be re enabled by setting the TESTNORM switch A1S2 to TEST after the HP5501B covers are removed LASER RADIATION IS ACCESSIBLE WHEN THE HP5501B COVERS ARE REMOVED AND THE TEST NORM SWITCH A...

Page 42: ...ollowing test equipment Digital Voltmeter HP Model 3435A 5 14 Preliminary Procedure 5 15 This adjustment must be made with the laser tube at room temperature If the laser High Voltage Power Supply A2 or heater has been on allow at least two hours with 15 Volts off before performing this procedure Regardless of whether power is on or off observe the safety precautions in paragraph 5 4 and proceed a...

Page 43: ...V and 0 31V This voltage is V A3TP11 b Record value of V A3TP11 measured in step 5 16 a c Calculate the heater adjust set point using the following equation d Vset 1 285 x V A3TP11 e Connect Digital Voltmeter plus lead to A3TP15 Connect the minus lead to A3TP1 See Figure 5 2 f Check that the voltage at A3TP15 equals Vset 1 millivolt as calculated in step b If not adjust A3R16 SET TEMP see Figure 5...

Page 44: ...indicated jumpers to the following positions 1 JMP2 REF ON LO 2 JMP4 HTR OK HI 3 JMP7 HEATER OFF 4 JMP8 CLK FREQ HI NOTE Setting the A3 jumpers causes the laser to come on soon after power is applied e Set the milliammeter to the 10 milliampere range f Clip the HP428B probe around the red Anode High Voltage Power Supply wire located underneath the laser tube See Figure 5 3 The arrow on the milliam...

Page 45: ...oubleshooting in Section 8 If the laser power output as measured in paragraph 4 9 is not greater than 120 microwatts at this current level the laser assembly may require replacement j Record the laser tube current in the ADJUSTMENT RECORD located at the end of this section k Turn off the system power supplies disconnect the probe set the TEST NORM switch to NORM and reinstall the laser head covers...

Page 46: ......

Page 47: ...mblies must be returned for credit For this reason assemblies required for on site spare parts stock must be ordered by the New Assembly part number Table 6 1 Exchange Assemblies Assembly HP Part No New Assembly HP Part No Exchange Assembly HP Part No Laser Assembly 05501 60102 05501 60202 05501 69102 6 6 ABBREVIATIONS AND REFERENCE DESIGNATIONS 6 7 Table 6 2 lists abbreviations used in the parts ...

Page 48: ...ximum or minimum on any mail order there is a minimum order amount for parts ordered through a local HP office when the orders require billing and invoicing c Prepaid transportation there is a small handling charge for each order d No invoices to provide these advantages a check or money order must accompany each order 6 13 Mail order forms and specific ordering information are available through y...

Page 49: ...nry mho conductance MIN minimum min minute time minute plane angle MINAT miniature mm millimeter MOD modulator MOM momentary MOS metal oxide semiconductor ms millisecond MTG mounting MTR meter indicating device mV millivolt mVac millivolt ac mVdc millivolt dc mVpk millivolt peak mVp p millivolt peak to peak mVrms millivolt rms mW milliwatt MUX multiplex MY mylar μA microampere µF microfarad µH mic...

Page 50: ...125 V 28480 2110 0691 A1J1 1251 8494 6 1 CONN POST TYPE 100 PIN SPCG 24 CONT 28480 1251 8494 A1J2 NOT ASSIGNED A1J3 1251 6010 8 1 CONNECTOR 3 PIN M POST TYPE 28480 1251 6010 A1J4 1251 5170 9 1 CONNECTOR 2 PIN M POST TYPE 28480 1251 5170 A1J5 1251 3448 0 1 CONNECTOR 4 PIN F CIRCULAR 28480 1251 3448 A1J6 1251 3449 1 1 CONNECTOR 4 PIN F CIRCULAR 45 28480 1251 3449 A1L1 9140 0171 3 2 INDUCTOR RF CH ML...

Page 51: ...0 1472 F A1R22 0698 3156 2 RESISTOR 14 7K 1 1 8W F TC 0 100 24546 CT4 1 8 T0 1472 F A1R23 0757 0278 9 RESISTOR 1 78K 1 1 8W F TC 0 100 24546 CT4 1 8 T0 1781 F A1R24 0698 3156 2 RESISTOR 14 7K 1 1 8W F TC 0 100 24546 CT4 1 8 T0 1472 F A1S1 3101 2878 3 1 SWITCH PB DPDT MOM 5A 60 VAC VDC 31918 MP A1S2 3101 2334 6 1 SWITCH SL DPDT SUBMIN 5A 125VAC DC PC 28480 3101 2334 A1TP1 0360 0535 0 3 TERMINAL TES...

Page 52: ...20 50VDC CER 28480 0160 0576 A3C27 0160 0576 5 CAPACITOR FXD 1UF 20 50VDC CER 28480 0160 0576 A3C28 0180 0309 4 1 CAPACITOR FXD 4 7UF 20 10VDC TA 56289 150D475XOO10A2 A3C29 0160 4557 0 CAPACITOR FXD 1UF 20 50VDC CER 16299 CAC04X7R104M050A A3C30 0160 4554 7 CAPACITOR FXD 01UF 20 50VDC CER 28480 0160 4554 A3C31 0160 4824 4 1 CAPACITOR FXD 680PF 5 100VDC CER 28480 0160 4824 A3C32 0160 4557 0 CAPACITO...

Page 53: ...8W F TC O 100 24546 CT4 1 8 T0 511R F A3R20 0757 0280 3 5 RESISTOR 1K 1 1 8W F TC 0 100 24546 CT4 1 8 TO 1001 F A3R21 0757 0280 3 RESISTOR 1K 1 1 8W F TC 0 100 24546 CT4 1 8 T0 1001 F A3R22 0757 0438 3 3 RESISTOR 5 11K 1 1 8W F TC 0 100 24546 CT4 1 8 T0 5111 F A3R23 0698 3457 6 RESISTOR 316K 1 1 8W F TC 0 100 28480 0698 3457 A3R24 0757 0438 3 RESISTOR 5 11K 1 1 8W F TC 0 100 24546 CT4 1 8 T0 5111 ...

Page 54: ...3 1251 5177 6 CONNECTOR SGL CONT PIN 031 IN BSC SZ 28460 1251 5177 A3TP14 1251 5177 6 CONNECTOR SGL CONT PIN 031 IN BSC SZ 28460 1251 5177 A3TP15 1251 5177 6 CONNECTOR SGL CONT PIN 031 IN BSC SZ 28460 1251 5177 A3TP16 1251 5177 6 CONNECTOR SGL CONT PIN 031 IN BSC SZ 28460 1251 5177 A3TP17 1251 5177 6 CONNECTOR SGL CONT PIN 031 IN BSC SZ 28460 1251 5177 A3TP18 1251 5177 6 CONNECTOR SGL CONT PIN 031...

Page 55: ...9 SERIES 2632 REVISION B A4CR1 1990 0770 1 1 PHOTODIODE ID 30NA MAX 32694 OP 913 SELECTED A4P1 1251 6778 5 1 CONNECTOR 4 PIN F POST TYPE 28480 1251 6778 A4 MISCELLANEOUS PARTS AND HARDWARE 0340 0907 8 1 INSULATOR XSTR NYLON 28480 0340 0907 A5 05501 60102 1 1 LASER TUBE ASSEMBLY 28480 05501 60102 NOT FIELD REPAIRABLE SEE TABLE 6 1 FOR LASER TUBE REPLACEMENT PART NUMBERS A6 05501 60101 0 1 SAMPLER A...

Page 56: ...1 FASTENER 1 4 TURN ASSY PANEL THKNS 28480 1390 0314 H12 2190 0584 0 2 WASHER LK HLCL 3 0 MM 3 1 MM ID 28480 2190 0584 H13 2190 0586 2 2 WASHER LK HLCL 4 0 MM 4 1 MM ID 28480 2190 0586 H14 3050 0891 7 7 WASHER FL MTLC 3 0 MM 3 3 MM ID 28480 3050 0891 H15 3050 0893 9 2 WASHER FL MTLC 4 0 MM 4 4 MM ID 28480 3050 0893 MP1 05501 00008 0 1 SAMPLER MOUNT 28480 05501 00008 MP2 05501 20215 3 1 LASER BASE ...

Page 57: ...HP5501B Replaceable Parts 6 11 6 14 Exploded View Figure 6 1 HP5501B Laser Head Exploded View ...

Page 58: ...ORS DIV TUSTIN CA US 92680 16299 CORNING ELECTRONICS RALEIGH NC US 27604 24546 CORNING ELECTRONICS SANTA CLARA CA US 95050 27014 NATIONAL SEMICONDUCTOR CORP SANTA CLARA CA US 95052 28480 HEWLETT PACKARD CO CORPORATE HQ PALO ALTO CA US 94304 31918 ITT SHADOW INC EDEN PRAIRIE MN US 55344 32293 INTERSIL INC CUPERTINO CA US 95014 32694 TRW OPTOELECTRONICS DIV CARROLLTON TX US 75006 32997 BOURNS INC RI...

Page 59: ...RED BY THIS MANUAL in Section 1 for additional important information about serial number coverage 7 3 Newer Instruments 7 4 As engineering changes are made newer instruments may have a higher serial number prefix than that listed for the particular instrument The manual shipped with a HP5501B Laser Head will include a Manual Changes sheet that describes all required changes to update the manual If...

Page 60: ......

Page 61: ...The descriptions are used with schematic diagrams for A1 A2 and A3 8 5 Recommended Test Equipment 8 6 Table 1 2 in Section 1 lists the test equipment required for service Any equipment that satisfies the critical specifications given in the table may be substituted for the recommended model s 8 7 Service Aids 8 8 This system uses both Metric and English hardware Figure 6 1 should be used to determ...

Page 62: ...HP5501B Service 8 2 Figure 8 1 Schematic Diagram Notes ...

Page 63: ... AND FUNCTIONING AND THAT ALL NECESSARY PARTS ARE CONNECTED TO THEIR PROTECTIVE GROUNDING MEANS FROM 1 2 KILOVOLTS TO 12 KILOVOLTS DC IS PRESENT ON THE ANODE OF THE LASER TUBE IN THE HP5501B EXERCISE EXTREME CAUTION WHEN WORKING INSIDE THE INSTRUMENT THE HIGH VOLTAGE COULD CAUSE SERIOUS PERSONAL INJURY IF CONTACTED THE INSTRUMENT SERVICE SHOULD BE PERFORMED BY SERVICE TRAINED PERSONNEL ONLY NOTE W...

Page 64: ... all exposed metal structures Indicates dangerous voltage at input or output terminals that may exceed 1000 volts Low noise or noiseless clean ground earth terminal Used for signal common as well as providing protection against electrical shock in case of fault A terminal marked with this symbol must be connected to ground as described in Section 2 Installation in this manual before operating the ...

Page 65: ...lso collimates the laser beam Collimating minimizes variations in the diameter of the beam as it travels away from the laser head Laser frequency F2 is polarized in a plane parallel to the base of the HP 5501B chassis The other laser frequency F1 is polarized perpendicular to F2 The difference between the two laser frequencies F1 and F2 is small compared to their optical frequencies The exit apert...

Page 66: ...HP5501B Service 8 6 Figure 8 2 HP5501B Laser Head Block Diagram ...

Page 67: ...t which it is heated The HP 55018 raises the cooling rate by maintaining the rod at an elevated temperature 8 29 Warmup Mode Tuning 8 30 One of two feedback loops used to control the laser assembly establishes the initial operating temperature of the glass rod When power is first applied to the HP 55018 the state machine see Figure 8 3 resets to its warmup mode In the warmup mode the state machine...

Page 68: ...oltage is amplified to provide the warmup mode error signal Figure 8 4 Feedback Loop during Warmup Mode 8 32 At the end of the 2 56 second disable period the heater coil temperature has settled to the rod temperature The error signal is sampled and held and the power amplifier is enabled During the remainder of the 25 6 second period the power amplifier re enabled and under control of the sampled ...

Page 69: ... as shown in Figure 8 6 The optical mode feedback controls the laser cavity length by measuring and comparing the power of the two laser frequency components Cavity length is controlled such that the difference in power is zero When the difference is maintained at zero the desired characteristics of the laser beam are established and a measurement can be performed Figure 8 6 Feedback Loop During O...

Page 70: ... splitters see Figure 8 7 and passing one of the laser frequency components then the other through an optical switch and onto a photodiode The beam splitters are part of the A6 Sampler Assembly and the photodiode is mounted on the A4 Sampler Board A liquid crystal and a polarizer comprise the optical switch Figure 8 7 A6 Sampler Assembly Exploded View ...

Page 71: ...both components by 90 degrees In this state the polarizer blocks the vertical component and passes the horizontal component The voltage out of the photodiode amplifier is proportional to the horizontal component and is held by the negative input of the subtracting sample and hold circuit The error signal output of the subtracting sample and hold circuit is proportional to any difference in power b...

Page 72: ...evels The frequency of the TTL output is the reference frequency The reference receiver electronics also provide a digital signal called REFERENCE RECEIVER ON REF ON that tells the state machine the laser is working properly 8 44 Shutter Mechanism 8 45 The exit aperture shutter of the shutter turret assembly has three positions The first blocks the laser beam entirely the second allows a small dia...

Page 73: ... JMP7 HEATER disables the power amplifier The CLK FREQ JMP8 allows the clock circuitry to generate either of the following three clock rates NRM 100 Hz HI 1000 Hz and with the jumper removed completely 75 kHz Test IC U9 is dummy 16 pin DIP package with no integrated circuit All of the important digital signals connect to U9 so that a logic clip can be used for monitoring NOTE There are two LO posi...

Page 74: ...in the laser head is required to troubleshoot or adjust the laser head circuits The following paragraphs describe how to remove the laser head covers and how to remove and reinstall the major assemblies HIGH VOLTAGES ARE GENERATED WITHIN THE LASER HEAD HOUSING THE COVERS OF THE LASER HEAD CONTROL A SAFETY INTERLOCK SWITCH A1S1 TO PREVENT ACCIDENTAL ACCESS TO THESE VOLTAGES TO ENSURE SAFETY AND POS...

Page 75: ...le through the opening c Using a suitable screwdriver rotate the fastener 1 4 turn in the counterclockwise direction see Figure 8 10 d Remove the front panel by gently pulling the panel straight away from the laser head e Remove the two half covers by gently pulling each cover outward and forward This releases the edges of the covers from the retaining grooves along the edges of the rear panel f T...

Page 76: ...procedure a Remove 15 Volt power from HP5501B Laser Head b Remove front panel and side covers as described in paragraph 8 55 c Remove two Pozidriv screws H7 that secure rear panel MP4 to laser base MP2 d Remove four Pozidriv screws H10 that secure A1 Connector board to rear panel assembly MP4 e Remove A3 Reference Controller Board Assembly as described in paragraph 8 58 ...

Page 77: ...e 15 Volts from HP5501B Laser Head b Remove front panel and side covers as described in paragraph 8 55 c Remove Pozidriv screw H5 and flat washer H14 that secures voltage regulator A3U7to the shield d Remove four Pozidriv screws H5 with flat washers H14 that secures A3 assembly to the shield e Gently extend front panel end of A3 away from shield in order to disengage A3J2 from A4P1 and also for A3...

Page 78: ...gure 8 11 Factory adjusted Sampler Mount MP1 8 60 To remove the A5 Laser Assembly HP Part No 05501 60102 from the HP5501B chassis perform the following procedure a Remove 15 Volt power from HP5501B Laser Head b Remove front panel and side covers as described in paragraph 8 55 c Disconnect laser assembly connector A5P1 from A1J4 d Remove two Pozidriv screws H7 that secures rear panel MP4 to laser b...

Page 79: ...all the laser assembly perform the reverse of the removal procedure ENSURE A2 HIGH VOLTAGE POWER SUPPLY CABLES ARE NOT PINCHED BETWEEN A5 LASER ASSEMBLY AND LASER BASE DURING REINSTALLATION OF LASER ASSEMBLY 8 61 The laser assembly consists of an aluminum housing laser tube magnets telescope and the quarterwave half wave plate assembly The telescope expands and collimates the beam The quarter wave...

Page 80: ...re working properly b Remove the HP5501B covers as described in paragraph 8 55 c Connect a dc coupled oscilloscope to A3TP16 on A3 as shown in Figure 8 13 Also see Figure 8 24 Component Locator for test point locations Figure 8 13 Quick Tuning Check Test Setup d Enable the laser high voltage section by setting the TEST NORMAL switch A1S2 on A1 Connector board to TEST e On A3 change HEATER jumper J...

Page 81: ...nce and a minimum difference Figure 8 14 Quick Tuning Check Waveform Display l Disconnect the test equipment and set HEATER jumper JMP7 to NRM Set TEST NORM switch to NORM and replace HP5501B covers 8 67 Testing the Liquid Crystal Switch 8 68 The following material and test equipment is required for the test a A white piece of cardboard b 50 Hz Square Wave Generator TTL Level c Test Polarizer HP P...

Page 82: ...current flow through the liquid crystal may damage the device c Gently place the probes of the 50 Hz signal source on the end shoulders of the liquid crystal as shown in Figure 8 16 and observe the window area it should go from light to dark while probing the device A faint change of color or no change indicates a faulty liquid crystal The replacement HP part number for the liquid crystal is 1990 ...

Page 83: ...d All electronic tests can be performed using an HP 5005A B Signature Multimeter WITH THE HP5501B COVERS REMOVED AND A1S2 SET TO THE TEST POSITION VOLTAGES OF UP TO 12 KV WILL BE PRESENT AT THE OUTPUT OF THE HIGH VOLTAGE POWER SUPPLY ASSEMBLY A2 NOTE After servicing the HP5501B be sure to set A1S2 to the NORM position otherwise power will be disconnected Figure 8 17 HP5501B TEST NORM Switch A1S2 ...

Page 84: ... the laser from reaching stable tuning d Disconnect power and remove the covers of the HP5501B Set A1S2 to TEST and verify that all boards are seated correctly and all test jumpers on the A3 board are in the left most position NRM e Connect power Check the following voltages If any are incorrect see Power Supply Troubleshooting in A3 Troubleshooting Procedures paragraph 8 151 or see A1 Connector B...

Page 85: ...on Troubleshooting paragraph 8 138 l If a REFerence frequency signal error is indicated after the laser has successfully reached normal operation READY LED on continuously and REFerence frequency signal output then make the following observation Does the READY LED extinguish when the failure occurs If so the optical tuning may be failing or the reference receiver may be resetting the state machine...

Page 86: ...ns the laser beam should be on This is accomplished by applying the WARMUP logic line through current limiting resistor A1R10 to the base of transistor A1Q4 A1Q4 saturates which in turn causes A1Q3 to turn on and saturate The high voltage power supply senses ground through saturated A1Q3 thus turns on 8 78 If the HP5501B left and right covers are placed on the unit prior to resetting the TEST NORM...

Page 87: ...own Check for proper transmission of power supply voltages Check for proper diode action across A1CR1 and A1CR2 Check A1C1 through A1C5 for shorts Check switches A1S1 and A2S2 Check A1R3 and A1R4 8 85 Rear Panel LED Operational Check MAINTENANCE DESCRIBED HEREIN IS PERFORMED WITH POWER SUPPLIED TO THE EQUIPMENT AND WITH THE PROTECTIVE COVERS REMOVED SUCH MAINTENANCE SHOULD BE PERFORMED ONLY BY SER...

Page 88: ...OFF i Disconnect power from laser head j Using a pair of insulated long nose pliers CAREFULLY return 15V fuse to its A1 board location Remove 15V fuse Pull fuse straight out DO NOT TWIST k Reapply power to laser head l The rear panel LED s should reflect the following status 15V SUPPLY UNBALANCE OFF 15V POWER ON OFF 15V SUPPLY UNBALANCE ON 15V POWER ON OFF 15V FUSE OFF READY OFF 15V FUSE ON LASER ...

Page 89: ...LTAGE POWER SUPPLY TROUBLESHOOTING LASER RADIATION IS ACCESSIBLE WHEN THE HP5501B COVERS ARE REMOVED AND THE TEST NORM SWITCH A1S2 IN THE TEST POSITION FROM 1 2 KILOVOLTS TO 12 KILOVOLTS DC IS PRESENT ON THE ANODE OF THE LASER TUBE IN THE HP5501B EXERCISE EXTREME CAUTION WHEN WORKING INSIDE THE INSTRUMENT THE HIGH VOLTAGE COULD CAUSE SERIOUS PERSONAL INJURY IF CONTACTED ANY MAINTENANCE SHOULD BE P...

Page 90: ...MMEDIATELY b Laser light is emitted but flashes or causes a REF Error 1 Turn power off and disconnect A1J4 Insert a 1K 1 0 5 Watt resistor Rt between the J4 pin 1 connector Leave J4 Pin 2 disconnected 2 Connect an oscilloscope across Rt 3 Turn on power and allow the laser to warm up 4 Observe DC test voltage It should be between 3 and 4 Volts If not perform the current adjustment procedure in Sect...

Page 91: ...HP5501B Service 8 31 Figure 8 18 High Voltage Power Supply Schematic Diagram ...

Page 92: ...ng purposes capacitors C3 C7 and C8 can be configured so that the oscillator circuit generates a 1000 Hz output JMP8 in HI position To troubleshoot using signature analysis the oscillator can be configured to run at 75 kHz 20 by removing the CLK FREQ jumper JMP8 completely 8 97 Dividers Ⓑ 8 98 The dividers consisting of U4A and U6 convert the 100 Hz oscillator signal into the desired periods The f...

Page 93: ...al on the falling edge of DISABLE to allow sufficient time for the heater coil to cool to the rod temperature See Figure 8 5 Warmup Mode Timing Diagram When the heater temperature rises to the proper value the HTR OK signal from U15 causes the output of U8A HTRQ to go high The state machine enters the heater qualified state and the READY LED blinks approximately twice per second The rate of blinki...

Page 94: ... component and the photodiode current is proportional to the horizontal component During the active state the photodiode current is proportional to the vertical component The output of U11D at TP16 is the photodiode current multiplied by an effective resistance of R20 R22 R17 R20 8 111 Warmup Error Amplifier and Comparator Ⓙ 8 112 The bridge formed by A1R15 and the heater on one side and A3R16 A3R...

Page 95: ... A1Q7 form the negative Darlington that drives the heater to 15 Volts A1Q5 provides downshifting of negative drive voltage level A3U20 is disabled at Pin 10 by A3U2C when the heater error voltage is sampled during the warmup mode The resistor networks A3R54A A3R54B A3R54C A3R65A A3R65C A3R65D and A3R66 drive the output Darlington s and limit the A3U21 input voltage to 5 Volts NOTE Positive and Neg...

Page 96: ...l coming out of the second amplifier When the amplitude exceeds 100 mV the voltage at A3U17 Pin 2 REF ON drops to TTL low A3Q6 A3CR6 and A3R45 shift the output of A3U17 to TTL levels A3 capacitors C22 C23 C24 C26 and C29 are used for coupling and bypass A TTL high on A3U17 Pin 11 LTO gates off the reference frequency output and raises A3U17 Pin 2 to Vcc 8 125 Line Driver Ⓚ 8 126 A3U16 provides the...

Page 97: ...t procedure places a group of IC s in a definite state and 1 Provides the correct values of the input and output signals characteristics OR 2 Implies use of the schematic to determine the signal characteristics OR 3 Simply states a suspected component b When the test procedure specifies a suspected component replace it and run the test again c When signal characteristics are known measure the sign...

Page 98: ...ST JUMPER IS IN THE OFF POSITION DAMAGE TO THE HIGH VOLTAGE POWER SUPPLY OR LASER ASSEMBLY COULD RESULT IF THESE INSTRUCTIONS ARE NOT ADHERED TO IMPORTANT NOTE Upon successful completion of a check unless otherwise specified return all test jumpers to their original position i e left most NRM position a With power disconnected remove front panel and side covers as described in paragraph 8 55 b Do ...

Page 99: ... U4 If no problem is found proceed to step f f Set HTR OK to HI REF ON to HI RESET to TEST Connect TP2 TP3 and Pin X of HTR OK jumper to ground TP1 or TP18 Set up the signature analysis clock start and stop signals for falling edge detection Using the signatures listed in step t localize the defective element by using standard signature analysis troubleshooting Begin with U9 and use the schematic ...

Page 100: ...A3 and the oscilloscope display The cycle begins with both LED s off and the voltage at U2C Pin 8 at TTL low The READY LED begins flashing and continues to do so for approximately 150 seconds About 100 seconds into the cycle the laser beam and the LASER ON LED turn on The READY LED continues to flash After 150 seconds the READY LED stops flashing and remains on steady Both LED s remain on only mom...

Page 101: ...ignature analyzer voltmeter function a Bypass high voltage interlock by setting A1S2 to TEST Set HTR OK jumper to LO PHOTO DIODE jumper to TEST LIQ CRYS jumper to PASS Is voltage at TP16 more negative than 4V If no go to step e If yes go to step b b Set LIQ CRYS jumper to ACT Is voltage at TP16 more positive than 1V If no go to step e If yes go to step d c Verify U11 Pin 13 is 0 V 10 m V If not re...

Page 102: ...ors HP Part Number 8160 0530 in A4 Assembly 8 144 Subtracting Sample and Hold Troubleshooting 8 145 This procedure assumes the digital circuit and photodiode and amplifier are functioning properly a Set REF ON jumper to LO and HTR OK to HI Wait for READY LED to remain on Set HTR OK to NRM Set PHOTO DIODE jumper to TEST and LIQ CRYS jumper to ACT Using a dedicated DC voltmeter check that the voltag...

Page 103: ...IQ CRYS to PASS POWER AMP to UP Verify TP16 voltage is approximately 5V Measure voltage at TP14 and record as V14 Measure voltage at U11A Pin 3 and record as V3 Measure voltage atTP12 Is it equal to 2 X V3 V14 within 30 mV If yes go to step o If no go to step n n Verify U11A Pin 2 is at the same voltage as U11A pin 3 lf not U11A or R15 bad Also check R14 R10 and R11 o This procedure thus far has s...

Page 104: ...o stay on Set POWER AMP jumper to UP Remove HEATER jumper Is voltage at U13 Pin 3 approximately 0 1V If not check A3R27 R31 R49 R50 R51 C18 and U13 If so go to step b b Within 1 minute of setting POWER AMP to UP is voltage at A3TP11 a nonsymmetrical square wave with peak voltages 13 Volts See Figure 8 20 If yes go to step d If not go to step c NOTE Figure 8 20 oscilloscope settings are as follows ...

Page 105: ...see A3 schematic for waveforms If waveforms and clock activity are OK check A1 power amp transistors for A1Q5 9 proper operation Check E REF input to U20 Pin 9 Waveform should be as in Figure 8 21 NOTE Figure 8 21 oscilloscope settings are as follows Time Division 20 microseconds division Volts Division 1 Volt division Coupling DC Figure 8 21 E REF U20 Pin 9 h Set HEATER jumper to OFF This applies...

Page 106: ...ty g Is A3U15 Pin 7 3 Vdc If yes go to step h If no A3R5E R48D U8A or U15 is bad h Remove TP15 short and short TP11 to ground Is A3U14 Pin 6 voltage 12 Vdc If yes go to step i If not U14 is bad i Is A3U15 Pin 7 between 0 05 and 0 15 If yes the warmup error amplifier is OK If no A3R5E R48D U8A or U15 is faulty 8 150 Power Supply Troubleshooting 8 151 If the correct voltage is not observed on A3TP8 ...

Page 107: ... 2 0 MHz If so the reference receiver may be working properly If not trace the signal path from U17 Pin 16 through A3Q6 to U16 Pins 5 6 and 7 TP22 and check for the following U17 Pin 16 0 3 to 0 7 Volt square wave at the Reference frequency of 1 5 to 2 0 MHz TP22 TTL level square wave at the REFerence frequency of 1 5 to 2 0 MHz A5J6 Rear Panel Connector Monitor Pins C and D with an oscilloscope W...

Page 108: ...la place a piece of paper between the laser assembly and the sampler assembly to block the laser beam The voltage at U17 Pin 10 should drop by 250 mV or more indicating adequate signal and the DC voltages listed in Table 8 6 should be measured on the pins of A3U17 with the beam blocked Table 8 6 A3U17 Reference Receiver Test Voltages PIN DC VOLTAGE POSSIBLE TROUBLE 9 12 14 Vcc 5 Vdc 15V External P...

Page 109: ...to examine the laser beam which is normally incident on the Reference Receiver photodiode Apply power to the HP5501B Examine the laser beam cross section illuminating the polarizer It should be circular and centered within a few millimeters with respect to the exit port Slight eclipsing is normal If any intensity variations are visible across the beam diameter they should be straight regularly spa...

Page 110: ...HP5501B Service 8 50 COMPONENT SIDE CIRCUIT SIDE SERIES 2632 REV A Figure 8 23 A1 Connector Board Component Locator ...

Page 111: ...HP5501B Service 8 51 Figure 8 23 A1 Connector Board Component Schematic Diagram ...

Page 112: ...Cathode Line Driver Analog Ground A1J6 B Ⓚ 12 24 REF Through A3C34 A3L5 to A3U16 1 2 A1J6 C Ⓚ 13 1 READY READY LED A1DS8 and A3DS1 Flashing A3U19 6 On Steady A3U19 10 Ⓕ 14 2 HEATER SENSE Through A3R21 to A3U14 2 A5 Heater Control A1TP3 or A3TP11 Ⓙ 15 3 Digital Ground 5501B Circuitry A1J5 D Ⓒ 16 4 17 5 15V Heater Control Drive A1Q8 A3U20 12 Ⓘ 18 6 15V 5501B Circuitry A1J5 A Ⓒ 19 7 Digital Ground 55...

Page 113: ...put 10 μsec Division 15 VOLTS 0 VOLTS 15 VOLTS A3TP11 or A1TP3 HEATER SENSE During Optical Locking Mode Oscilloscope Settings Vertical Input 5 Volts Division Horizontal Input 10 μsec Division 4 VOLTS 0 VOLTS A3U20 Pin 3 U20 s Internal Oscillator Output Waveform 50 kHz Oscilloscope Settings Vertical Input 2 Volts Division Horizontal Input 10 μsec Division Waveform photographs taken with all test ju...

Page 114: ...l Input 20 μsec Division A3U20 Pins 12 and 13 15 Volt Heater Control Drive Output Waveform 25 kHz Oscilloscope Settings Vertical Input 2 Volts Division Horizontal Input 10 μsec Division A3U20 PIN 11 A3U20 PIN 12 15 VOLTS A3U20 Pin 9 E REF or Subtracting Sample and Hold Difference Input Waveform Oscilloscope Settings Vertical Input 1 Volts Division Horizontal Input 20 μsec Division A3U20 PIN 13 15 ...

Page 115: ...ABBREVIATION FOR COMPLETE DESCRIPTION 2 UNLESS OTHERWISE INDICATED 3 RESISTANCE IN OHMS CAPACITANCE IN FARADS INDUCTANCE IN HENRIES 4 ASTERISK INDICATES FACTORY SELECTED COMPONENT AVERAGE VALUE SHOWN 5 A TILDE PRECEDING A SIGNAL INDICATES A NEGATIVE TRUE SIGNAL 6 TEST IC A3U8 IS A DUMMY 16 PIN DIP PACKAGE WITH NO INTEGRATED CIRCUIT ALL THE IMPORTANT DIGITAL SIGNALS CONNECT TO A3U8 SO THAT A LOGIC ...

Page 116: ...HP5501B Service 8 56 Figure 8 24 A3 Controller Reference Board 05501 60027 and A4 Sampler Board 05501 60029 Schematic Diagram Sheet 2 of 2 ...

Page 117: ...20 2096 SN74LS383N U7 1820 0122 7805UC U8 1260 0510 SAME U10 1820 2466 1CM7555IPA U11 1826 0753 MC34004BL U12 1826 0416 LF13331D U13 1826 0493 MLM308AP1 U14 1826 0519 TL071CP U15 1826 0065 LM311N U16 1826 2668 SN75114N U17 1826 0775 IDA7Q U18 1826 3562 SN74ALS1005N U20 1826 0428 SG3524J U21 1826 1272 SN74LS33N Reference Designations A3 ASSY CI C45 CR1 2 5 8 DS1 2 J1 2 JMP1 8 L1 5 Q6 7 R2 8 10 11 1...

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Page 119: ...ther un predictable laser head performance This service note is important addition to the manual instructions when replacing the laser tube or the control board Solution Action 1 After the Laser Tube or the control board has been replaced the heater voltage must be correctly readjusted The adjustment is done with the pot R16 to the right of U11 on the control board 2 The adjustment must be perform...

Page 120: ...djust set point using the following equation Vset 1 285 X V A3TP11 0 005 Volts 6 Measure A3TP15 and adjust A3R16 until it equals Vset to 1 millivolt 7 Turn off the laser head Move the HEATER jumper from OFF to NRM and PLUG J3 the HV Power Supply back onto it s connector on A1 8 Turn on the laser head again and wait until it locks NOTE If the laser does not lock wait for two hours and repeat Step 1...

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