OKI CX2731MFP
Troubleshooting. LCD Display Trouble
LCD displays nothing
Check item | Checking | Action in case of fail |
---|---|---|
Checking fuse | ||
Fuse on SU PCB | Check whether F2 has blown. | Replace F2 or SU PCB. |
Checking connections | ||
Connection between lowvoltage power supply unit and SU PCB | Make sure the low-voltage power supply unit is connected to the POWER connector on the SU PCB properly. Check whether the cable connector is half-connected or tilted, or whether wires are broken. Check whether there is any fault in the cable assembly, e.g., missing wires. |
Connect the cable properly. |
Cable assembly connecting low-voltage power supply unit to SU PCB | Replace the cable with a good cable. | |
Connection between SU PCB and operation panel | Make sure the 16-pin FFC is connected to the OPE connector on the SU PCB properly. Make sure the 16-pin FFC is connected to the CN1 connector on the operation panel PCB properly. Check whether the cable connector is half-connected or tilted. |
Connect the cable properly. |
FFC connecting SU PCB to operation panel PCB | Check for broken wires using a tester. Check visually whether the sheath peels. |
Replace the cable with a good cable. |
Checking power supplies | ||
AC power supplied to the printer | Check the supplied voltage from the AC power source. | Supply AC power. |
5V power supplied to SU PCB | Check the 5V power at 3, 4pin of the POWER connector on the SU PCB. | Replace the low-voltage power supply. |
3.3V power supplied to operation panel PCB | Check the 3.3V power at 14pin of the CN1 connector on the operation panel PCB. | Replace the SU PCB. |
Checking for short circuit of power supply | ||
5V and 24V power supplied to SU PCB | Check for a short circuit using the POWER connector on the SU PCB.7, 8pin: 24V 3, 4pin: 5V 5, 6pin: 0VL 9, 10pin: 0VP If there is a short circuit, locate it. Disconnect the cables from the SU PCB one by one to locate the short circuit. |
Replace the shortcircuited component. |
Checking LSI operation | ||
I/F signal from SU PCB to operation panel PCB | Check whether signals are output to the OPE connector on the SU PCB. 9pin: Transmission data (sent from the SU PCB) 11pin: Clock 13pin: Enabling 15pin: Reset Signals should be always output under normal conditions. |
Replace the SU PCB. |
Display of OKI logo
Check item | Checking | Action in case of fail |
---|---|---|
Operation panel display does not change | ||
Operation panel display | OKI logo stays on. | Replace the SU PCB. |
Error message display
Check item | Checking method | Action in case of fail |
---|---|---|
Error message | ||
Error message display | Check the detail of the error on the error message list. | Follow the instructions. |