Oki C9850 Maintenance Manual page 193

Power is turned on and the printer doesn't work properly.
• Turn off power and on again.
• Does the backlight light up (for approx. one second)?
• NO
• YES
• YES
• YES
• YES
• YES
(a)
43627911TH Rev. 3
Is the AC cable connected properly?
NO Connect the AC cable properly.
Is the power supply indicator LED of the Main PCB on?
• NO Does power go off when power is turned on again 2 minutes
after power is turned off?
• YES Is the fuse F503 of the Engine PCB blown?
YES Replace the Engine PCB.
• NO Are the Engine PCB FFC (inserting DRV0 and DRV1 connec-
tors) and the power connector cable properly connected to the
Motor Driver PCB and the power supply?
NO Connect them properly or replace the FFC or the ca-
ble.
• YES Replace the power supply.
Is the DIMM of the Main PCB set properly?
NO Set the DIMM properly. If that does not solve the problem, re-
place the DIMM.
Is the operator panel cable connected properly?
NO Connect the cable properly.
Is +5V output to the panel connector (OPEPANE) of the Engine PCB (S2V
PWB)?
Pin 5: +5V, Pin 2: 0V
• NO Is +5V output to the DENGEN connector of the Engine PCB (S2V
PWB)?
Pins 1 & 3: +5V, Pins 2 & 4: 0V
NO After checking the DENGEN connector, replace the
Low-Tension Power Supply Unit.
• YES Replace the Engine PCB.
Is the problem solved after the Control Panel PCB (X7G PWB) is re-
placed?
YES End
NO Replace the Engine PCB.
Oki Data CONFIDENTIAL
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