Ricoh Aficio IS420 Page 39 Service Manual Download

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2.5.2. MBU (Mother Board Unit)

The MBU passes signals between boards and generates the timing clocks for
the CCD.

The MBU has four LEDs (LED1~LED4) on the dc power lines. The
relationship between the LEDs and the dc power is as follows.

LED1

+24V

LED2

+5V

LED3

+12V

LED4

-5V

ADU

SBU

SDU

Electrical

components

Timing signal

generator

SCU

PSU

Video data

+24V, +12V, ±5V

G404D504.wmf

Det

Descriptions

October 9th, 1995

DETAILED SECTION DESCRIPTIONS

PCBs AND THEIR FUNCTIONS

2-21

Summary of Contents for Aficio IS420

Page 1: ...IMAGE SCANNER IS420 HS 1P SERVICE MANUAL Ricoh Co Ltd October 1995 ...

Page 2: ...t daß dieses Gerät in Übereinstimmung mit den Bestimmungen der Verfügung Nr 1046 des Amtsblatts Nr 163 1984 funkentstört ist Installing the Interface Connector The use of cables other than the shielded I O cables or equivalent specified will invalidate the certification of this Scanner and may cause interference levels which exceed the limits estab lished for this equipment Safety Information The ...

Page 3: ...ed intervals 3 Toner and developer are non toxic but if you get either of them in your eyes by accident it may cause temporary eye discomfort Try to remove with eye drops or flush with water as first aid If unsuccessful get medical attention OBSERVANCE OF ELECTRICAL SAFETY STANDARDS 1 The copier and its peripherals must be installed and maintained by a customer service representative who has compl...

Page 4: ... The laser subsystem is replaceable in the field by a qualified Customer Engineer The laser chassis is not repairable in the field Customer engineers are therefore directed to return all chassis and laser subsystems to the factory or service depot when replacement of the optical subsystem is required WARNING Use of controls or adjustment or performance of procedures other than those specified in t...

Page 5: ...ed trademarks of International Typeface Corporation Times Helvetica and Palatino are registered trademarks of Linotype AG and or its subsidiaries Lotus and 1 2 3 are registered trademarks of Lotus Development Corporation Microsoft is a U S registered trademarks of Microsoft Corporation Microsoft Word MS DOS and Windows are registered trademarks of Microsoft Corporation Arial Monotype and Times New...

Page 6: ...scales 8 bits pixel Initialization time About 20 seconds Scanning speed 1 4 s 200 dpi A4 binary picture mode 3 s 200 dpi A3 binary picture mode Scanning throughput 36 ppm 200 dpi A4 binary picture mode 18 ppm 400 dpi A4 binary picture mode Counted from the second page Interface SCSI 2 high density Video interface option Power 1 85 to 138 V ac 45 to 65 Hz 2 176 to 276 V ac 45 to 65 Hz Power consump...

Page 7: ...r interlock switch Also contains an exposure glass 3 Scale Used for positioning a document when placing it on the exposure glass 4 Power switch Turns the power on and off 5 Scanner indicator lamps The green and orange lights indicate the condition of the scanner 6 Main exposure glass A document to be scanned in book mode is placed face down on this glass 1 2 3 4 5 6 g404v501 wmf OVERALL MACHINE IN...

Page 8: ...SCSI ID and to select diagnostic tests Note that positions 8 and 9 are interpreted as SCSI ID 7 10 DIP switches Used to select various scanning modes and test modes 11 Reset switch If this is pressed the machine is reset 12 Power plug inlet For connecting the power cord 9 11 12 7 10 8 g404v502 wmf Overall Information October 9th 1995 OVERALL MACHINE INFORMATION COMPONENT LAYOUT 1 3 ...

Page 9: ...ced in the input tray 17 Document support wire If long documents are placed in the input tray this helps to feed them correctly 18 Exit table Receives documents fed by the ADF after scanning 19 Exit table extension This holds the documents output from the ADF it can be extended to support long documents 20 ADF indicator lamps The green and orange lights indicate the ADF operation condition 13 14 1...

Page 10: ...means of a mirror 3 Guide rails Hold the first and second carriages and guide their movement 4 Scanner drive wires Transmit motor power to the 1st and 2nd carriages 5 Motor gear box The gears in this box drive the motor belts that drive the scanner 6 Motor belt 2 Transmit motor power to the scanner drive wires 7 Motor belt 1 8 Pulleys Hold the scanner drive wires 9 Wire spring Tightens the scanner...

Page 11: ...oller Picks up and transports the top page of the original placed on the document table 13 Feed out rollers Feed the scanned original onto the exit table 14 Paper transport drum Transports the original to the scanning position 15 Paper transport rollers Hold the original against the paper transport drum 10 12 11 13 15 14 g404v505 wmf OVERALL MACHINE INFORMATION October 9th 1995 DRIVE LAYOUT 1 6 ...

Page 12: ...CD and converts the light reflected from the original into a video signal 8 MBU This contains circuits for dc power distribution and interfaces with other boards 9 SCU This contains a CPU an interface circuit and other circuits 10 Platen cover interlock switch Detects whether the platen cover is open or closed and cuts the power supply to the machine 11 ADF exposure cover interlock switch Detects ...

Page 13: ...e input tray is at the feed position or not approximate location indicated in this diagram 18 ADU This contains circuits for the ADF s motors sensors and other electrical components 19 Document table lift clutch Switches on to lift the document table up or down 20 Pick up clutch Controls pick up roller rotation 21 Read sensor Detects when a document is just before the reading position 22 Feed sens...

Page 14: ...ed This red lamp causes red parts of originals such as lines on OCR forms not to be reproduced in the image data After a red lamp has been installed the machine adjusts the image processing circuits automatically to account for the lower signal level from the CCD The VIU and DCU cannot both be installed at the same time 26 23 24 25 g404v510 wmf Overall Information October 9th 1995 OVERALL MACHINE ...

Page 15: ...document 3 1st mirror Reflects light from the document to the second mirror 4 Lens Focuses the light from mirrors 1 2 and 3 onto the CCD on the SBU 5 2nd mirror Reflects light from the first mirror to the third mirror 6 3rd mirror Reflects light from the second mirror to the lens 1 2 3 6 5 4 g404v508 wmf OVERALL MACHINE INFORMATION October 9th 1995 OPTICAL LAYOUT 1 10 ...

Page 16: ...e it amplifies the signal and sends it to the MBU PSU Power Supply Unit This supplies 24V 5V and 12V to the MBU SDU Scanner Drive Unit This controls the motors lamp and other components in the scanner SDP Scanner Display Panel This lights up green and orange LEDs to indicate the scanner condition ADU ADF Drive Unit This controls the motors sensors and other components in the ADF ADP ADF Display Pa...

Page 17: ...the video interface DCU Data Compression Unit This is an optional board for compressing the scanned image data by methods known as MH MR and MMR IEU Image Enhancement Unit This carries out image processing functions OVERALL MACHINE INFORMATION October 9th 1995 CONTROL SYSTEM OUTLINE 1 12 ...

Page 18: ...ne on each power line to indicate the condition of each power supply Read SN ADP Scanner Indicator Panel Home Position SN Feed out SN Cooling Fan Motor AC Switching Circuit ADF Exp Cover Interlock SW Platen Cover Interlock SW 5V 5V 5V 12V 5V 5V 24V 12V 24V SDU 24V ADU 5V 5V 12V 24V 5V 5V 12V 24V 5V Document Table Position SN Document SN Feed SN 5V 5V 5V 5V 24V ADU Document Table Lift CL Pick up CL...

Page 19: ... No Initialize the SIP3 Yes Turn on the lamp Do CH1 and CH2 of the D A converter initialize correctly Shading error No Initialize the motor Yes Is the home position check OK Home position error No Scan the white plate Yes Is the peak level more than the specified value User Level Service Level Lamp error No Yes 1 2 3 4 5 6 7 8 9 A B G404D516 wmf Detailed Descriptions October 9th 1995 DETAILED SECT...

Page 20: ...tion procedure been tried three times User Level System error Service Level Indicates which error occurred Yes Are the ADF or the document feeder cover closed No ADF open error No Is any one of the feed read or exit sensors on Yes Paper jam Yes Is there any paper on the document table No No Is the document table working properly Document table error Yes READY No Yes 10 11 12 13 14 15 16 17 18 Yes ...

Page 21: ... carriages If the CPU does not detect a signal change within the specified period it determines that a home position error has occurred 9 Checks the peak level of the auto gain control of the SIP3 If this value is below the specified value the CPU determines that a lamp error has occurred 10 Checks the minimum level of the white plate image data If this value is below the specified value the CPU d...

Page 22: ...e is a paper jam 16 Checks the document sensor signal If a document is detected on the document table check 17 is not performed 17 Checks the document table position sensor signal timing while lifting and lowering the document table 18 See step 13 DETAILED SECTION DESCRIPTIONS October 9th 1995 INITIALIZATION 2 4 ...

Page 23: ...Image Scanning There are two rectangular black marks A and B 2 x 2 mm for scanner position fine adjustment The mark A is not used but the mark B is used for moving the carriage to the exact scan start position At the start of scanning the scanner moves from the scanner home position and looks for the mark The machine uses the black mark to move to the exact scan start position which is nearby C B ...

Page 24: ...al vertically The 2nd carriage D which contains the 2nd E and 3rd F mirrors moves to keep the distance between the document and the CCD constant 3 Scanner Reversing After the image has been scanned the carriages return to the home position The carriages are stopped when the first carriage activates the home position sensor If the scanner home position sensor is not activated within a certain time ...

Page 25: ...at the leading edge such as a tear extending more than 1 mm across the paper and more than 5 mm down the paper the machine will not scan the document past this gap 1 2 Sub Scan Direction Document Length The scanner scans the maximum length The scanner determines the document length in the sub scan direction from the output signal level The edge of the document is detected by the difference between...

Page 26: ... direction The scanner determines that the document length is the same as for a standard paper size of the same width Note The scanner always assumes the paper is in a lengthwise orientation i e the main scan is the short side Also in USA models if Letter width is detected the paper is always assumed to be Letter size the last few inches of a Legal size original will not be scanned After detecting...

Page 27: ... is detected the carriages B will stop The first carriage moves to the ADF scanning position C from the scanner home position D Then the paper transport motor starts SADF Mode The scanner waits until the desginated time for the originals to be placed on the document table A When the originals have been placed on the document table the same procedure as for ADF mode is carried out A B C D G404D508 ...

Page 28: ... the bend in the lift shaft pushes up the document table see the next page for a diagram When the top of the document stack is pushed up against the pick up roller it can rise no more However the mechanism continues to push up against the tray until a half turn of the shaft has been completed i e until the actuator leaves the document table position sensor At that time the document table lift clut...

Page 29: ...lways against the pick up roller When all pages of the original have been fed out of the ADF the document table lift clutch and paper feed motor are energized to lower the tray They turn off when the document table sensor is deactivated If the sensor is not deactivated within the desginated time a document table error will occur H I g404d532 wmf Detailed Descriptions October 9th 1995 DETAILED SECT...

Page 30: ...he feed roller D the separation mechasnism is friction based When the leading edge of the original activates the feed sensor E the paper feed motor and the pick up clutch turn off then the original is fed by the paper transport drum F to the scanning position 4 Image Scanning The scanner starts to scan the image when the leading edge has passed the read sensor by a certain distance measured by mot...

Page 31: ... 5 mm past the first carriage During this operation the CPU detects the original width The edge of the document is detected by the difference between the level of the document data and the background level which is provided by the black bracket located over the ADF exposure cover If there is a gap at the leading edge such as a tear extending more than 1 mm across the paper and more than 5 mm down ...

Page 32: ...ata to the host computer 2 2 Auto Size Mode This mode can be set with the Set Window command which is invoked by the driver software If the scanner is set in the Auto Size Mode it detects the document size only in the main scan direction After this width detection the scanner starts scanning the detected width The scanning length is determined by the detected length 3 Abort and Unload commands The...

Page 33: ...n 3 0 33 0 29 1 24 1 31 1 2 0 26 400 dpi A3 lengthwise 11 x 17 Binary picture processing Within 3 Within 3 0 66 0 58 3 51 3 64 2 4 0 51 0 52 800 dpi A4 sideways Grayscale processing Within 9 Within 9 3 95 3 47 10 5 11 3 14 3 3 06 3 12 G404D500 wmf Detailed Descriptions October 9th 1995 DETAILED SECTION DESCRIPTIONS PAPER MISFEED DETECTION 2 15 ...

Page 34: ... The trailing edge of the original does not pass through the read sensor within the time required for feeding the original length 30 mm after the feed sensor has been activated J5 The trailing edge of the original does not pass through the feed out sensor within the time required for feeding the original length 30 mm after the feed sensor has been activated If an original jam or an original non fe...

Page 35: ...r Error Diffusion Data Compression Unit DRAM Control Dynamic Thresholding Auto Photo Line Separation SCSI Control SIMM DRAM Video I F Adapter Host Computer Host Computer SBU IEU SCU Option Slot White peak data Odd pixel data Even pixel data Analog data Binary processing Grayscale processing G404D502 wmf Detailed Descriptions October 9th 1995 DETAILED SECTION DESCRIPTIONS VIDEO DATA PATH 2 17 ...

Page 36: ...ain range of the amplifier is controlled by the CPU on the SCU board by monitoring the feedback signals from the shading correction circuit 5 A D Conversion The amplified analog signals are converted to 8 bit digital signals This gives 256 gradations for each pixel 6 Shading Correction The machine scans the white plate opposite the ADF exposure glass to make a white waveform Shading correction pre...

Page 37: ...ging the scanner speed However reduction and enlargement in the main scan direction are done by the software 10 Mirror Processing A mirror image of the original must be made for output 11 Dithering Dither processing produces good quality grayscale images of photo originals 12 Error Diffusion The error diffusion process reduces the difference in contrast between light and dark areas of a halftone i...

Page 38: ...l signal The CCD sends both odd and even pixel video signals to the multiplexer where these signals are merged The signal is amplified and digitized then sent to the SCU SCU CCD Sample hold Sample hold Multiplexer Gain control A D converter Ref White level selection Relative Absolute G404D505 wmf DETAILED SECTION DESCRIPTIONS October 9th 1995 PCBs AND THEIR FUNCTIONS 2 20 ...

Page 39: ...s LED1 LED4 on the dc power lines The relationship between the LEDs and the dc power is as follows LED1 24V LED2 5V LED3 12V LED4 5V ADU SBU SDU Electrical components Timing signal generator SCU PSU Video data 24V 12V 5V G404D504 wmf Detailed Descriptions October 9th 1995 DETAILED SECTION DESCRIPTIONS PCBs AND THEIR FUNCTIONS 2 21 ...

Page 40: ...d SRAM 8 kbytes x 3 is used as an image data buffer SBC Scan Buffer Controller Stores the image data from the SIP3 in the memory DRAM 512 kbytes x 2 Address control when recalling the data from the memory SCSI controller SCSI Interface controller SRAM Work area 32 kbytes EPROM Contains the program Enhanced I O Extension for the I O port DIP switches mode selection rotary switches SCSI ID setting a...

Page 41: ...n and drive current for the scanner motor come from the SCU through the MBU Also the control signal for the xenon lamp comes from the SCU through the MBU Drive circuit Inverter circuit Scanner motor Xenon lamp Motor signal 5V 24 VSDU Lamp control signal G404D507 wmf Detailed Descriptions October 9th 1995 DETAILED SECTION DESCRIPTIONS PCBs AND THEIR FUNCTIONS 2 23 ...

Page 42: ...he ADU through the MBU The drivers on the ADU convert the control signals into drive pulses for the motors Feed out sensor Read sensor Feed sensor Document sensor Document table position sensor Driver Motor driver Motor driver Pick up clutch Document table lift clutch ADF Paper transport motor Paper feed motor Sensor signals 5V 24V Drive signals G404D503 wmf DETAILED SECTION DESCRIPTIONS October 9...

Page 43: ...ures Do not expose the scanner to dusty or corrosive atmospheric conditions Ensure that the area in which the scanner is used is well ventilated Make sure that the surface on which you place the scanner is stable and level 3 1 1 Environmental Conditions Temperature Humidity 10 to 32 C 50 to 90 F 20 to 80 3 1 2 Space Requirements The following are the minimum space requirements to ensure proper ven...

Page 44: ... 3 3 PACKING When transporting the scanner do the following 3 3 1 Power Cord 1 Make sure that the power switch is off 2 Pull out the power cord from the wall outlet 3 Pull out the power cord from the scanner 4 Coil the power cord and place it into the inner box 3 3 2 Packing Move the carriage to its home position this locks it into position Set the shipping pads on the right and left of the scanne...

Page 45: ...witches 3 and 4 These are for factory use only Service level test modes Various tests for the scanner are carried out using dip switches 5 to 8 Within each test mode tests are selected by turning the SCSI ID rotary switch and the machine s condition is indicated by the four LEDs on the covers Note the position of the SCSI ID rotary switch before you change it To return to normal operation mode aft...

Page 46: ...dicated in the same way as described above for ADF mode refer to Table E later in this section Unit 1 sheet Max value 1000K sheets Xenon lamp on time indication The total illumination time of the lamp is indicated in the same way as above Unit 1 hour Max value 3000 hours EEPROM reset mode After the dip switches are set to on and the reset switch is held down for more than 3 seconds all LEDs are tu...

Page 47: ...the demonstration e g mis feed jam etc the scanner stops and the LEDs indicate the error condition Table B Component Test Mode Rotary Switch No Contents 0 All components off 1 Lamp on off 1 2 Not used 3 Clutches on off 2 4 Not used 5 Not used 6 Not used 7 Not used 8 Not used 9 Not used 1 When the reset switch is pressed to start the test the lamp turns on and off repeatedly 2 When the reset switch...

Page 48: ...cted sensor is off all LEDs turn off Table D Self Diagnostic Mode The following error conditions are indicated by a combination of four LEDs Error Items Scanner LEDs ADF LEDs Amber Green Amber Green Memory error Blinking Shading error Blinking Origin positioning error Blinking Blinking Lamp failure Blinking Blinking On On Document table error On Blinking Blinking Home position error Blinking Blink...

Page 49: ... On LED on LED off Use the rotary switch to select a digit of the counter The value of the selected digit is indi cated by a combination of the four LEDs For the LEDs ON represents a 1 and OFF a 0 The four LEDs are read off as a four bit number Example Rotary switch no LED condition scanner green amber ADF green amber 1 units ON OFF OFF OFF 1000 8 2 tens OFF OFF ON ON 0011 3 3 hundreds OFF ON OFF ...

Page 50: ... VR4 See Appendix B Electrical Adjustments 4 3 SPECIAL TOOLS Part Number Part Name G4049000 Scanner Positioning Tool 2 pcs set G4049002 Optical Adjustment Harness Jig Harness G4049001 Optical Adjustment Glass Jig Glass A0129110 Resolution Chart G4049003 RS 13 Chart A5 G4049005 RS 13 Chart A4 G4049004 RS 13 Chart A3 55 kg G4049006 RS 13 Chart A3 90 kg H2039114 RS 12 Chart A3 G4043102 White Sheet SE...

Page 51: ...ect the power cord and interface cable s for safety 5 1 COVERS 5 1 1 ADF Upper Cover A ADF Upper Cover 2 screws 5 1 2 ADF Left and Right Covers A ADF Left Cover 1 screw 1 connector B ADF Right Cover 1 screw A G404R500 wmf A B G404R501 wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT COVERS 5 1 ...

Page 52: ...5 1 3 Left Cover 5 1 4 Right Cover A B G404R502 wmf A ADF Exposure Cover B Left Cover 2 screws A G404R503 wmf A Right Cover 2 screws REMOVAL AND REPLACEMENT October 9th 1995 COVERS 5 2 ...

Page 53: ...1 3 and 5 1 4 A Front Cover 2 screws 1 connector 5 1 6 Rear Cover First remove the left and right covers see section 5 1 3 and 5 1 4 A Knob Screw B Rear Cover 2 hooks A G404R504 wmf A B G404R505 wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT COVERS 5 3 ...

Page 54: ...remove the ADF Upper Cover see section 5 1 1 ADF Left Cover and ADF Right Cover see section 5 1 2 A Paper Transport Drum B Paper Transport Unit 2 E rings 2 springs 2 connectors B A G404R506 wmf REMOVAL AND REPLACEMENT October 9th 1995 ADF AND UPPER SIDE 5 4 ...

Page 55: ...move the ADF Upper Cover see section 5 1 1 ADF Left and ADF Right Covers see section 5 1 2 A Separation Unit 4 screws 3 connectors A G404R507 wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT ADF AND UPPER SIDE 5 5 ...

Page 56: ...Separation Unit see section 5 2 2 A Document Table Assembly 3 screws 5 2 4 Scanning Guide Plate First open the platen cover A Scanning Guide Plate 2 screws G404R509 wmf A A G404R511 wmf REMOVAL AND REPLACEMENT October 9th 1995 ADF AND UPPER SIDE 5 6 ...

Page 57: ...e Document Table Assembly see section 5 2 3 A Paper Feed out Assembly 1 stepped screw 1 connector B Upper Feed out Unit C Lower Feed out Unit B A C G404R512 wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT ADF AND UPPER SIDE 5 7 ...

Page 58: ...crews 1 harness B Paper Transport Motor 2 screws 1 harness C Motor Cushions D Spring Plates 5 2 7 ADU First remove the ADF Left Cover see section 5 1 2 A ADU 4 screws 5 connectors 2 flat cables C A D B C G404R513 wmf A G404R514 wmf REMOVAL AND REPLACEMENT October 9th 1995 ADF AND UPPER SIDE 5 8 ...

Page 59: ...xit Table Extension B Paper Output Guide C Platen Cover 4 screws D Platen Cover Support Brackets Note When replacing the platen cover take out all harnesses routed on the platen cover carefully B A D C D platencv wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT ADF AND UPPER SIDE 5 9 ...

Page 60: ... Assembly First remove the Left Cover and Right Cover see section 5 1 3 and 5 1 4 and Front Cover see section 5 1 5 A ADF Exposure Cover B Main Exposure Glass Assembly B A G404R516 wmf REMOVAL AND REPLACEMENT October 9th 1995 LOWER SIDE 5 10 ...

Page 61: ...on 5 3 5 A 3 screws to loosen B Timing Belt C Scanner Motor Assembly 4 screws 1 connector Before taking out the motor assembly loosen the scanner drive wire timing belt To do this loosen three screws A B A G404R517 wmf C G404R518 wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT LOWER SIDE 5 11 ...

Page 62: ...ction 5 3 7 A Upper Unit 6 screws 2 flat cables Note Open the platen cover while removing the upper unit or the upper unit will be damaged B Right Side Plate 8 screws C Left Side Plate 8 screws A G404R526 wmf B C G404R527 wmf REMOVAL AND REPLACEMENT October 9th 1995 LOWER SIDE 5 12 ...

Page 63: ... screw 1 connector F Reflector G Xenon Lamp H Lamp Holder 1 screw I Wire Securing Plates 1 screw each J First Carriage Assembly E D G404R508 wmf F G I I J H G404R528 wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT LOWER SIDE 5 13 ...

Page 64: ...tioning tools A into positioning holes B and C 3 Thread the scanner wire through the hooks D in the carriage 4 Install the wire securing plates see I on the previous page 5 Remove the positioning tools 6 Reassemble the machine D A D C B A G404R536 wmf REMOVAL AND REPLACEMENT October 9th 1995 LOWER SIDE 5 14 ...

Page 65: ...ection 5 3 1 A Upper Unit 6 screws Note Open the platen cover while removing the upper unit or the upper unit will be damaged B Right Side Plate 8 screws C Left Side Plate 8 screws A G404R510 wmf C B G404R538 wmg Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT LOWER SIDE 5 15 ...

Page 66: ... D Tension Spring E Scanner Wires F Second Carriage Assembly 1 Route the scanner wires as shown above D F E E R404R529 wmf G404R530 wmf REMOVAL AND REPLACEMENT October 9th 1995 LOWER SIDE 5 16 ...

Page 67: ...the machine 4 Insert the carriage positioning tools B into positioning holes C and D 5 Tighten the allen screws in the pulley 6 Remove the positioning tools 7 Reassemble the machine A G404R531 wmf B B D C G404R537 wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT LOWER SIDE 5 17 ...

Page 68: ...ield Plate 8 screws B Rear Shield Plate 5 screws C Flat Cable 5 3 6 Power Switch Assembly First remove the main exposure glass see section 5 3 1 A Key Top B Power Switch 2 screws C Switch Wire B C A G404R519 wmf C B A G404R520 wmf REMOVAL AND REPLACEMENT October 9th 1995 LOWER SIDE 5 18 ...

Page 69: ...s Block Assembly First remove the front shield plate see section 5 3 5 A Lens Block Assembly 4 screws 3 flat cables A G404R521 wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT LOWER SIDE 5 19 ...

Page 70: ... Bracket 2 screws C SCU NOTE When replacing the SCU put the old ROM IC13 on the new SCU 5 4 2 SDU First remove the front shield plate see section 5 3 5 A SDU 4 screws 3 connectors C B A G404R522 wmf A R404R523 wmf REMOVAL AND REPLACEMENT October 9th 1995 PCBs 5 20 ...

Page 71: ...ction 5 4 1 A MBU 4 screws 4 connectors 2 flat cables 5 4 4 PSU First remove the front shield plate and rear shield plate see section 5 3 5 A Power Switch Cable B PSU 4 screws 2 connectors B A G404r525 wmf A G404R524 wmf Replacement Adjustment October 9th 1995 REMOVAL AND REPLACEMENT PCBs 5 21 ...

Page 72: ...t feeder cover closed 4 Paper jam Is there a paper jam 5 Document table error System error Does the document feeder table work properly 6 Memory error System error Does the memory in the scanner work properly 7 Shading error System error Has the scanner done shading correction correctly 8 Origin positioning error System error Has the scanner detected the origin position properly 9 Home position er...

Page 73: ...s are checked during operation They are not checked in stand by mode except for ADF exposure cover open and Document feeder cover open 1 Paper jam Is there a paper misfeed 2 All items listed in Section 6 2 1 TROUBLESHOOTING October 9th 1995 CHECK ITEMS 6 2 ...

Page 74: ...l prefeeding No On Blinking Yes On On Scanning Normal mode No On On Yes On On On User visible Error Conditions ADF cover interlock sw is open Blinking Blinking On Lamp error Blinking Blinking On On Platen cover interlock sw open On On Document jam On On Blinking Document misfeed On On On Document table error On Blinking Blinking System Error Blinking Blinking Blinking Blinking On LED on Blinking L...

Page 75: ...open Symptom The error remains even if the ADF exposure cover is closed properly Possible Cause ADF exposure cover broken ADF exposure cover interlock switch is broken The SCU is broken The harness between the switch and SCU is damaged 24V power line failure Procedure Does 24 volts come to the interlock switch Yes No Is the harness damaged Yes No Replace the SCU Replace the harness Replace the int...

Page 76: ...No Is the PSU harness damaged Yes No Replace the PSU Replace the harness Does the SDU generate 24 volts Connect the tester probes to pin 1 and 2 of CN3 Yes No Replace the SDU Replace the lamp harness Are all mirrors installed properly Yes No Reseat any mirrors that are out of place Does the SBU generate the correct signals Yes No Replace the SBU Replace the SCU If that does not work try changing t...

Page 77: ...ver interlock switch is damaged The harness between the platen cover interlock switch and the SCU is damaged The MBU is damaged Procedure Does 24 volts come to the platen cover interlock switch Yes No Is the harness damaged Yes No Replace the MBU Replace the harness Replace the platen cover interlock switch TROUBLESHOOTING October 9th 1995 TROUBLESHOOTING PROCEDURES 6 6 ...

Page 78: ...the sensors OK Yes No Is the harness damaged Yes No Replace the defective sensor Replace the harness Does the jam always happen at the same position Yes No Is the 24 volt line from the MBU to the ADF for the transport motor OK Yes No Is the harness damaged Yes No Replace the MBU Replace the harness Are the 24 volt lines from the ADU to the motors OK Yes No Is the harness damaged Yes No Replace the...

Page 79: ...roken The ADU is broken The SCU is broken The feed sensor is broken Procedure Does the pick up roller mechanism work Yes No Is 24 volts supplied to the pick up clutch Yes No Is the harness damaged Yes No Replace the ADU Replace the harness Is there an open circuit in the clutch Yes No Replace the SCU Replace the pick up clutch Does the jam happen at the separation unit Yes No Replace the pick up r...

Page 80: ...e feed motor and the document table lift clutch Yes No Is the harness damaged Yes No Replace the ADU If the 24 volts from the MBU has is defective another error will be generated Replace the harness Replace the motor or the clutch if it has a break in its internal wiring Replace the separation roller Replace the SCU Note If the 5 volts line is defective the ADF LEDs will not work so the error type...

Page 81: ... SCU is broken Procedure Is the SCSI interface being used Yes No Replace the SCU 2 Origin Positioning Error This error is detected when the scanner fails to detect the origin position Possible Cause There is some dust on the origin position sensor patch Procedure Clean the sensor patch 3 Lamp Error Same as for the user visible error condition See section 6 4 1 4 Document Table Error Same as for th...

Page 82: ...maged SBU damaged The lamp is defective The shading seal is dirty Procedure Is there any problem with the lamp Yes No Is the shading seal dirty Yes No Are all the mirrors installed properly Yes No Reseat the mirror Does the SBU generate the correct signals Yes No Replace the optical unit Replace the SCU Replace the ADF cover Replace the lamp Note The read signal goes to the SCU through the MBU but...

Page 83: ...The MBU is damaged Procedure Does the home position sensor work Check it with sensor test mode See page 4 2 Yes No Does 5 volts reach the sensor Yes No Is the harness between the home position sensor and the MBU OK Yes No Replace the harness Replace the MBU Replace the sensor Is the drive wire OK Yes No Replace it Does 24 volts reach the scanner motor Yes No Is the harness between the motor and th...

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Page 86: ...is detected by the CCD 2 MTF Modulation Transfer Function adjustment Adjustment of focus to where the CCD detects the greatest image signal level 3 Magnification adjustment Adjustment of the magnification to where a 400 dpi image is formed on the CCD 4 Horizontal scanning starting position adjustment Adjustment to determine the position at which reading of a document starts in the horizontal scann...

Page 87: ...of the chart is against the ADF exposure glass NOTE Make sure that the end of the test chart with the thin white line pattern is on the edge E of the glass that is nearest the ADF exposure glass 6 Loosen the four screws on the SBU 7 Set dip switches 1 7 and 8 to the ON position 8 Set the SCSI rotary switch to 1 9 Turn on the power I CAUTION Cover the transformer with some paper to avoid electric s...

Page 88: ...e probes of the oscilloscope as shown above CN1 V CN2 T 3 Turn the adjustment knobs on the SBU to where the CCD detects the white level the white level trace must be flat and the output is greatest G404X501 wmf G404X502 wmf Time 0 1 ms V 1 V G404X508 wmf Appendix A October 9th 1995 APPENDIX A OPTICAL ADJUSTMENT MECHANICAL Adjustment A 3 ...

Page 89: ...on 2 Loosen the lens retaining screw then move the lens as indicated by the arrow to where the oscilloscope waveform output is maximized 3 Tighten the lens retaining screw to immobilize the lens G404X503 wmf V 1 V T 0 1 ms G404X509 wmf A G404X515 wmf APPENDIX A OPTICAL ADJUSTMENT MECHANICAL October 9th 1995 Adjustment A 4 ...

Page 90: ... the optical block back and forth to where the number of waveform intersections displayed is reduced to six or less 2 Tighten the two optical block retaining screws G404X504 wmf V 1 V T 0 1 ms G404X510 wmf Appendix A October 9th 1995 APPENDIX A OPTICAL ADJUSTMENT MECHANICAL Adjustment A 5 ...

Page 91: ...the read position 2 Change the time range setting of the oscilloscope to 5 µs Move the SBU left or right to where the time between the dummy bit and the beginning of the effective read data is 12 8 2 5 µs G404X505 wmf 12 8 2 5 µs G404X511 wmf V 0 5 V T 5 µs APPENDIX A OPTICAL ADJUSTMENT MECHANICAL October 9th 1995 Adjustment A 6 ...

Page 92: ...re the CCD output becomes as shown above right Note Turning the adjustment knob on the SBU may disturb the horizon tal scanning starting position adjustment Check whether the ad justment has been affected and adjust if necessary 3 Tighten the screws on the CCD board A 3 7 Final White Level Adjustment Repeat the White Level Adjustment procedure G404X512 wmf G404X508 wmf V 1 V T 0 1 ms A G404X515 wm...

Page 93: ...oss or Straight VIU Video Interface Unit G4045901 Jig Glass G4049001 White Chart G4043102 Gray Chart Note The white and gray charts should be attached to the jig glass with adhesive tape as shown in the following diagram Note that the gray chart should be attached to the glass with its printed gray side in contact with the glass The white chart should be attached to the glass with its white side n...

Page 94: ...log output level when the machine scans a white sheet is adjusted White level for background detection mode Relative white level This adjusts the analog ASIC peak hold value used for generating the reference voltage of the A D converter Analog image data is converted to digital data using this reference voltage B 4 Adjustment Procedure B 4 1 Setup 1 Make sure that the exposure glass has been remov...

Page 95: ...n the Windows accessories 7 Select Communications in the Settings menu 8 Set up each item as follows Baud Rate 9 600 Data Bits 8 Stop Bits 1 Parity None Flow Control None 9 Switch on the scanner The scanner initialization messages appear HS1P b TEST Program 92 10 21 Start 95 01 09 0R25 by M Miya Y Hatt F Kita SIP3 RESET Initial chk start 001 KURO GAP OK e o 0011 0011 KURO AJST END e o 0003 0002 SH...

Page 96: ...command is already send ex p100 move lump 100mm from home position 2 Type 1 then press Enter Calcurate White Level Mesurement CCD output voltage 377usec after TP1 s falling edge Input Data CCD output voltage mV 3 Input 400 then press Enter Target White Level 220 Next Hit Enter Key 4 Press the Enter key The Gain Curve Adjustment begins AJUST GAIN CURVE Put the Gray Chart on the Lamp position Then H...

Page 97: ...99 9 Adjust VR2 on the SBU until the value of X is within the required range In the example screen above the value on the bottom line below the X must be 99 2 Then input This ends the Gain Curve Adjustment EXIT Finish gain curve ajustment Next Hit Enter Key 10 Press the Enter key The Gain Curve Confirmation procedure starts CONFIRM GAIN CURVE Absolute white level W1 AGC 11 Ajust VR4 X 220 2 Image ...

Page 98: ...y X 002 002 087 084 085 082 003 083 Ave O 084 E 082 003 083 15 Check that X is within the required range In the example screen above the value on the bottom line below the X must be 90 10 Then press If X is not within the required range do the Gain Curve Adjustment procedure again complete the entire adjustment procedure without adjusting anything then start again from the beginning EXIT If NG aju...

Page 99: ...White Chart on the Lamp position Then Hit Enter Key 21 Make sure that the 1st carriage is at the white chart position Then press the Enter key AGC 27 Absolute white level W1 Ajust VR4 X 220 0 10 Image Data 3584 Exit key X 002 002 219 217 217 215 002 216 Ave O 217 E 214 002 215 22 Adjust VR4 on the SBU until the value of X is within the required range In the example screen above the value on the bo...

Page 100: ...E 216 004 217 25 Adjust VR1 on the SBU until the value of X is within the required range In the example screen above the value on the bottom line below the X must be 218 3 Then input EXIT Finish white level relative ajustment Finish All Ajustment The adjustment procedure has finished Switch off the scanner remove the VIU and reassemble the machine APPENDIX B OPTICAL ADJUSTMENT ELECTRICAL October 9...

Page 101: ...2 FEATURES For high speed processing the input output data processing in the DCU is 16 bit To make the DCU compact the FPGA is used for both data input and output processing C 3 BLOCK DIAGRAM 8 bit to 16 bit Converter 8 bit to 16 bit Converter FIFO 1 5k x 8 bits FIFO 2 5k x 8 bits SBC DRAM 4 Mbits x 2 Address Decoder Selector Selector DICEP E1 I O Controller FPGA Function Register A0 A7 D0 D7 VDAT...

Page 102: ...2 BLOCK DIAGRAM The IEU consists of the following 8 blocks 1 DIB Video Data Input Block The DIB has the following functions controlling the input of multi value 8 bit video data generating the line reset signal and the page reset signal and transmitting multi value video data to the GTB 2 BIB Binary Video Data Input Block The BIB has the following functions controlling the binary video input data ...

Page 103: ...rrection interfacing with the FIFO memory and transmission of data to the ZMB 5 ZMB Zooming Mirroring Block The ZMB has the following functions changing magnification mirroring images interfacing with SRAM and data transmission to the DOB 6 DOB Video Data Output Block The DOB has the following functions generating text photo separation data black white image inversion serial parallel conversion MS...

Page 104: ...r and the host computer There are two connectors from the VIU to the host computer Scanner control interface Video interface for sending image data to the host computer Host Computer Control I F Video I F VIU Scanner SCU G404O502 WMF Appendix E October 9th 1995 VIU VIDEO INTERFACE UNIT OVERVIEW E 1 ...

Page 105: ... E 2 2 Signal Description TxD Response to the command from the host scanner to host RxD Command from the host host to scanner RTS The scanner requests to send data to the host scanner to host CTS The host is ready to receive data from the scanner host to scanner DTR The scanner is ready to send or receive data scanner to host DSR The host is ready to send or receive data host to scanner Host VIU C...

Page 106: ...or the main scan direction host to scanner VGATE Gate signal for the sub scan direction scanner to host V0 V7 Video data 0 Black Fail Indicates that the scanner has a ROM RAM error Host VIU Video I F VCL HGATE VGATE V0 V7 FAIL G404O504 WMF Appendix E October 9th 1995 VIU VIDEO INTERFACE UNIT VIDEO INTERFACE E 3 ...

Page 107: ...h 2 Switch Type 1 bit DIP switch Function Normal Service Mode Selection Settings 1 off Service Mode on Normal Mode Default E 4 3 DIC Switch Switch Type 8 pairs of jumper pins Function 1 4 Cable Type Selection 5 8 Normal Service Mode Selection Settings Cable Selection Straight Cable Short pins 1 and 3 Default Cross Cable Short pins 2 and 4 pins Mode Selection Normal Mode Short pins 5 and 8 Default ...

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