Lexmark 4227-X00 Service Manual page 39

4227-X00
FRU/Symptom
2 Machine power
sometimes turns
off.
3 Intermittently poor
print quality.
2-16
Service Manual
Action
The cause of this problem may be that the
power circuit is failing, or the wiring is
intermittently open. Check the following in
sequence:
1. Check the electrical voltage and be sure it is
within tolerance.
2. Check the continuity of the power cord.
3. Disconnect the power supply cable from the
connectors CN11 on the main logic board
and CN1 on the sub logic board. Turn the
printer power on and check all dc output
voltages at CN11 and CN1.
Be sure the output voltages are as follows:
CN11-1 (+40 ±4 V dc) & CN11-3 (GND)
CN11-2 (+40 ±4 V dc) & CN11-3 (GND)
CN11-5 (+5 ±0.5 V dc) & CN11-6 (Signal GND)
CN 1-1 (+40 ±4 V dc) & CN1-3 (GND)
CN 1-2 (+40 ±4 V dc) & CN1-3 (GND)
CN 1-5 (+5 ±0.5 V dc) & CN1-6 (Signal GND)
If one of the voltages is 0, go to the
Failure Service Check" on page 2-25
voltages are not 0 but are incorrect, replace the
power supply unit.
Do the following:
• Remove paper jams from the paper path.
• Clean all feed roller surfaces.
• Clean the ribbon shield and printhead.
• Clean the platen surface.
• Install the ribbon cartridge correctly.
• If the ribbon end of life has been reached,
have the customer replace the ribbon
cartridge.
"Power
. If the