Konica Minolta bizhub 25e, Field Engineering Manual

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4-37
4.8 Machine malfunction
No. Symptom What to confirm Countermeasure
1 The LCD shows
nothing. 1. Is the machine in energy save mode? Yes
No
Press the energy save key, and release
the mode.
Check No.2.
2. Is the power cable plugged correctly? Yes
No
Check No.3.
Plug the cable correctly.
3. Is the power switch On? Yes
No Check No.4.
Power on.
4. Does the DC output voltages from
the power supply unit to connector
P3 on the main control boar have the
following output?
Pin 1, 2, 3, 4 +24V
Pin 14 +3.4V
Pin 5, 6, 7, 8, 11, 13 GND
Yes
No Check No.5.
Replace the power supply.
5. Is the following connection OK?
• LCD assembly to the Panel PCB. (P3)
• Panel PCB (P1) to the harness to the
main control board. (P5A)
Yes
No Check No.6.
Reconnect the connection or replace
the harness.
6. If you replace the panel board, the
symptom will be fixed.
Yes
No Replace the panel board.
Check No.7.
7. If you replace the main control board,
the symptom will be fixed.
Yes
No Replace the main control board.
Replace the machine.
2
The LCD shows
“Please close
the flashing
cover.” 1. If you close the flashing cover, the
symptom will be fixed.
Yes
No Solved.
Check No.2.
2. Is the cover secured firmly by
screws?
Yes
No Check No.3.
Secure the cover properly.
3. Is the message shown after energy
save mode is released?
Yes
No Check No.4.
Check No.5.
4. Does the main control board P21-1
have +24V output?
Yes
No Check No.5.
Check No.6.
5. Press the sensor in the message and
check the output changes to +3.3V
through GND.
(The interlock and JAMC +24V
through GND.)
No Replace the sensor or the harness.
ADF cover :
ADF control board P3-8 Yes Check No.6.
Interlock and JAMC :
Main control board P21-2 Yes Check No.7.
6. If you replace ADF board or the
connecting harness, the message will
disappear.
Yes
No Replace the circuit board or the
harness.
Check No.7.
7. If you replace the main control board,
the symptom will be fixed.
Yes
No Replace the main control board.
Replace the machine.