Error Code - Lexmark C750 Service Manual

5060-00x

127 Error code

Backup roll thermistor or thermistor circuits are open
The printer detects a problem in the fuser back up roll, circuits, fuser backup roll thermistor, engine board, or
LVPS fuser control circuits.
Step Action and questions
Turn the printer on and allow it to reach Ready.
1
Note: The printer may not complete POR and post a
127 error message.
Remove the fuser assembly from the printer and
measure the voltage on connector J10-7 on the engine
board. The voltage should measure approximately
+3.3 V dc.
Is the voltage correct?
2 Measure the voltage on pin 7 of the fuser DC control
connector. See
voltage should measure approximately +3.3 V dc.
Is the voltage correct?
128 Error code
Fuser hot roll is under temperature during standby.
Step Action and questions
Turn the printer on to allow it to reach Ready.
1
Note: The printer may not complete POR and continue
to display a 128 error message.
Remove the fuser assembly from the printer and
measure the voltage on connector J10-6 on the engine
board. The voltage should measure approximately
+3.3 V dc.
Is the voltage correct?
2 Measure the voltage on pin 6 of the fuser DC control
connector on the LVPS. The voltage should measure
approximately +3.3 V dc.
Is the voltage correct?
2-48
Service Manual
"Engine board" on page
Yes
Go to step 2
Replace the fuser
5-7. The assembly. See
"Fuser assembly
removal" on
page 4-31.
Yes
Go to step 2
Replace the fuser
assembly. See
"Fuser assembly
removal" on
page 4-31.
No
Replace the engine
board. See
"Engine board
removal" on
page 4-29.
Replace the LVPS.
See "Low voltage
power supply
(LVPS) removal"
on page 4-38.
No
Replace the engine
board assembly.
See "Engine
board removal"
on page 4-29.
Replace the LVPS
assembly. See
"Low voltage
power supply
(LVPS) removal"
on page 4-38.