Lexmark C750 Service Manual - Page 81

Lexmark C750 Manual

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5060-00x 125 Error code Hot fuser The printer detects a problem with the fuser running over temperature or the backup rolls have been on too long. A problem could exist in the fuser assembly with the backup roll bearings, backup roll thermistor, or other backup roll parts. The LVPS or engine board assembly may also be failing. Step 1 Action and questions Open the right fuser access door. Observe the fuser and see if the backup roll lamp turns on and off. You may have to observe the fuser for a few minutes. Does the backup roll lamp turn off and on? Yes Go to step 2 No Replace the LVPS assembly. See "Low voltage power supply (LVPS) removal" on page 4-38. Replace the engine board assembly. See "Engine board removal" on page 4-29. 2 Turn the printer on and measure the voltage on connector J10-12 on the engine board. The voltage should measure approximately +0.13 V dc to +0.64 V dc as the hot roll lamp turns on and off. Is the voltage correct? Replace the fuser assembly. See "Fuser assembly removal" on page 4-31. 126 Error code Hot roll thermistor or thermistor circuits are open The printer detects a problem in the fuser hot roll, hot roll lamp circuits, fuser hot roll thermistor, engine board, or LVPS fuser control circuits. Step 1 Action and questions Turn the printer on and allow it to reach Ready. Note: The printer may not complete POR and post a 126 error message. Remove the fuser assembly from the printer and measure the voltage on connector J10-6 on the engine board. See "Fuser connectors" on page 5-25. The voltage should measure approximately +3.3 V dc. Is the voltage correct? 2 Measure the voltage on the fuser DC control connector on the LVPS. Measure the voltage on pin 6 of the connector. The voltage should measure approximately +3.3 V dc. Is the voltage correct? Replace the fuser assembly. See "Fuser assembly removal" on page 4-31. Replace the LVPS assembly. "Low voltage power supply (LVPS) removal" on page 4-38. Yes Go to step 2 No Replace the engine board. See "Engine board removal" on page 4-29. Diagnostic information 2-47

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Diagnostic information
2-47
5060-00
x
125 Error code
Hot fuser
The printer detects a problem with the fuser running over temperature or the backup rolls have been on too long.
A problem could exist in the fuser assembly with the backup roll bearings, backup roll thermistor, or other backup
roll parts. The LVPS or engine board assembly may also be failing.
126 Error code
Hot roll thermistor or thermistor circuits are open
The printer detects a problem in the fuser hot roll, hot roll lamp circuits, fuser hot roll thermistor, engine board, or
LVPS fuser control circuits.
Step
Action and questions
Yes
No
1
Open the right fuser access door. Observe the fuser
and see if the backup roll lamp turns on and off. You
may have to observe the fuser for a few minutes.
Does the backup roll lamp turn off and on?
Go to step 2
Replace the LVPS
assembly. See
“Low voltage
power supply
(LVPS) removal”
on page 4-38
.
2
Turn the printer on and measure the voltage on
connector J10-12 on the engine board. The voltage
should measure approximately +0.13 V dc to
+0.64 V dc as the hot roll lamp turns on and off.
Is the voltage correct?
Replace the fuser
assembly. See
“Fuser assembly
removal” on
page 4-31
.
Replace the engine
board assembly.
See
“Engine
board removal”
on page 4-29
.
Step
Action and questions
Yes
No
1
Turn the printer on and allow it to reach
Ready
.
Note:
The printer may not complete POR and post a
126 error message.
Remove the fuser assembly from the printer and
measure the voltage on connector J10-6 on the engine
board. See
“Fuser connectors” on page 5-25
. The
voltage should measure approximately +3.3 V dc.
Is the voltage correct?
Go to step 2
Replace the engine
board. See
“Engine board
removal” on
page 4-29
.
2
Measure the voltage on the fuser DC control connector
on the LVPS. Measure the voltage on pin 6 of the
connector. The voltage should measure approximately
+3.3 V dc.
Is the voltage correct?
Replace the fuser
assembly. See
“Fuser assembly
removal” on
page 4-31
.
Replace the LVPS
assembly.
“Low
voltage power
supply (LVPS)
removal” on
page 4-38
.