Oki ES3640MFP Service & Troubleshooting Manual page 104

Power Supply Fan Failure
Error Codes that Apply
121
Initial Troubleshooting Actions to Take
1. Clear any obstructions from the LVPS Fan vent.
2. Cycle the printer's power.
3. If the problem persists follow the procedure below.
Parts of the Printer that Apply
1. LVPS Fan
2. LVPS
3. Engine Control Board
Troubleshooting Procedure
Steps
1
Run the Motor Clutch Test
Does the Fan operate correctly?
Check the LVPS Fan connection.
2
Is the fan securely connected?
Verify +24 volts is available to the
3
Fan. Disconnect the Fan and test at
connector. Is there +24 volts at the
Action Taken
Test the LVPS Fan.
FAN POWER
Fan connector?
Yes
Replace the Engine
Control Board
Go to Step 3.
Replace the LVPS Fan
No
Go to Step 2.
Reconnect the
Fan.
Replace the LVPS