Konica-Minolta bizhub C759
Troubleshooting. Do not display the trouble code
Machine is not energized at all (DCPU operation check)
Relevant electrical parts
• Main power switch (SW1)
• MFP board (MFPB)
• DC power supply unit (DCPU)
Procedure
| Step | Check item | Location | Result | Action |
|---|---|---|---|---|
| 1 | Is a power voltage supplied across CN001-1 and 2 on DCPU? | 22-L | NO | Check wiring from power outlet to DCPU CN001. |
| 2 | Are the fuses on DCPU conducting? | NO | Replace DCPU. | |
| 3 | Is DC5 V being output to CN006-5 to 8 on DCPU? | 23-L | NO | • Check wiring from MFPB CN42E to SW1. • Replace DCPU. |
| 4 | Is DC24 V being output to CN007-3 on DCPU after the main power switch has been turned ON? |
22-J | NO | • Check wiring from MFPB CN29E to DCPU CN009. • Replace DCPU. • Replace MFPB. |
| 5 | The LED on MFPB is blinking after the main power switch has been turned ON? | NO | Replace MFPB. | |
| 6 | Is DC24 V being output to CN007-1 on DCPU with the doors closed after the main power switch has been turned ON? | 22-J | NO | Replace DCPU. |
Power is not supplied to DF
Relevant electrical parts
• DC power supply (DCPU)
• DF
Procedure
| Step | Check item | Location | Result | Action |
|---|---|---|---|---|
| 1 | Is DC24 V being output from CN1 on DF? | 25-J | YES | Malfunction in DF. |
| 2 | Is DC24 V being output from CN004-1 on DCPU? | 24-J | NO | Check wiring from DCPU to DF. |
| 3 | Are the fuses on DCPU conducting? | YES | Replace DCPU. | |
| NO | Malfunction in DF. |
Power is not supplied to LU-205/LU-303
Relevant electrical parts
• DC power supply (DCPU)
• LU-205/LU-303
Procedure
| Step | Check item | Location | Result | Action |
|---|---|---|---|---|
| 1 | Is DC24 V being output from relay CN425? | 11-W | NO | Malfunction in LU-205/LU-303. |
| 2 | Is DC24 V being output from CN20-1 on PFTDB? | 11-U | NO | Check wiring from PFTDB CN20 to LU-205/LU-303. |
| 3 | Are the fuses on DCPU conducting? | YES | Replace DCPU. | |
| NO | Malfunction in LU-205/LU-303. |
Power is not supplied to FS-536/FS-536SD/FS-537/FS-537SD
Relevant electrical parts
• DC power supply (DCPU)
• FS-536/FS-536SD/FS-537/FS-537SD
Procedure
| Step | Check item | Location | Result | Action |
|---|---|---|---|---|
| 1 | Is DC24 V being output from CN1-1 of FN? | 24-J | NO | Malfunction in finisher. |
| 2 | Is DC24 V being output from CN004-5 on DCPU? | 24-J | NO | Check wiring from DCPU to finisher. |
| 3 | Are the fuses on DCPU conducting? | YES | Replace DCPU. | |
| NO | Malfunction in finisher. |
MFP does not start
Relevant electrical parts
• MFP board (MFPB)
Procedure
| Step | Check item | Location | Result | Action |
|---|---|---|---|---|
| 1 | Check whether trouble occurs and the message saying that MFP attempts to restore backup data appears. | YES | Attempt to restore backup data. | |
| 2 | Rewrite the firmware and check whether that works. | NO | ||
| 3 | Check whether replacing the MFP board works. | NO | Contact the responsible people of KM before taking some countermeasures. |