Error Code - Lexmark C750 Service Manual

Step Action and questions
3 Check for continuity between pins 1 and 2 on the AC
fuser connector located on the fuser assembly.
Is there continuity?

121 Error code

An incorrect fuser backup roll lamp is installed.
CAUTION: Make sure the lamp is cool before removing it from the assembly.
Step Action and questions
1 Is the correct fuser assembly installed in the printer?
2 Is the correct fuser backup roll lamp installed in the
fuser assembly?
3 Check for continuity between pins 2 and 5 on the AC
fuser connector located on the fuser assembly.
Do you have continuity?
Yes No
Replace the LVPS Replace the fuser
assembly. See assembly. See
"Low voltage "Fuser assembly
power supply removal" on
(LVPS) removal" page
on page 4-38.
Yes No
Go to step 2 Install the correct
fuser assembly.
See
assembly
removal" on
page
Go to step 3 Install the correct
fuser backup lamp.
Replace the LVPS Replace the fuser
assembly. See assembly. See
"Low voltage "Fuser assembly
power supply removal" on
(LVPS) removal" page
on page 4-38.
Diagnostic information
5060-00x
4-31.
"Fuser
4-31.
4-31.
2-45