Oki C7500n Maintenance Manual page 128

2 Dirty Background. (Fig. 5-2 B )
• Was the image drum exposed to external light for a long time?
Yes Replace the I/D unit.
M •
No Is the roller in the fuser unit dirty?
Yes Replace the fuser unit.
M •
No Correct the PAPER THICKNESS setting.
Light: 64 g/m
Medium Heavy: 91 to 104 g/m
Transparency
No Set [Paper Thickness] properly.
M •
No Is the LED head assembly connected properly to the connection board (Y73 PWB)?
No Connect the LED head assembly properly to the connection board (Y73 PWB).
M •
Yes Is +5V output to the following power pins on the connection board (Y73 PWB)?
+5V: Pin 1, 2, 3, 4, 5, 6
• Yes Is +5V output to the following cable connector pins between the connection board (Y73
PWB) and LED head assembly?
3 pin for YPOW connector : LED head assembly - yellow
3 pin for MPOW connector : LED head assembly - magenta
3 pin for CPOW connector : LED head assembly - cyan
3 pin for KPOW connector : LED head assembly - black
No Replace the connection board (Y73 PWB).
M • Yes Check the cable connections, then replace the LED head assembly.
M •
No Check the cable connections, then replace the low-voltage power unit. Did the printer
recover?
Yes End.
M •
No Is 34V output to the power connector on the engine board (K7N/K7V PWB)?
+34V: Pin 12, 13, 14
No Check the cable connections, then replace the low-voltage power unit.
M •
Yes Is 34V output to the power connector pin 2 on the engine board (K7N/K7V PWB)?
+34V: Pin 12, 13, 14
No Replace the engine board.
M •
Yes Check the cable connections, then replace the high-voltage power unit or belt cassette
assembly.
Yes End.
M •
No Is the I/D unit terminal connected properly to the contact assembly. (See Fig. 5-2)
No Connect the I/D unit terminal properly to the contact assembly.
M •
Yes Replace the image drum unit.
Note: 1. Remove EEPROM from the old board and set it on the new board upon replacing the
engine board (K7N PWB).
2. If EEPROM is not replaced, refer to section 3.2.2.
3. When replacing the engine board (K7V PWB), upload EEPROM data from the board and
then download it to a new board, using a life counter tool.
41955801TH Rev.8
2
Medium Light: 64 to 74 g/m
2
Heavy: 105 to 120 g/m
2 2
Medium: 75 to 90 g/m
2
Ultra Heavy 121 to 203 g/m
Oki Data CONFIDENTIAL
2
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