Lexmark C734 series, Service Manual

Page: 167 / 436

Diagnostic information
2-133
5026
Print quality—horizontal line
The photoconductor unit is defective. Replace the photoconductor unit.
Print quality—insufficient fusing
Print quality—missing image at edge
Reseat the developer cartridge.
Print quality—mottle (2–5mm speckles)
Keep running prints through, and the problem normally clears up. If the problem persists, replace the developer
cartridge.
Print quality—narrow vertical line
Print quality—random marks
Service tip: The primary cause of random marks is due to loose material moving around inside the printer and
attaching to the photoconductor unit, developer roll, or transfer module.
Step Questions / actions Yes No
1 Is the fuser properly installed? Go to step 2. Install the fuser properly.
2 Replace the fuser. See “Fuser removal” on
page 4-90 .
Does this fix the problem?
Problem solved. Replace the LVPS. see
“Low-voltage power
supply (LVPS) removal”
on page 4-98
.
Step Questions / actions Yes No
1 Replace the photoconductor unit. See
“Photoconductor unit removal” on
page 4-118
.
Problem solved. Replace the print cartridge.
Step Questions / actions Yes No
1 Is there any loose or foreign material on the
photoconductor unit? Replace the
photoconductor unit. See
“Photoconductor unit
removal” on page 4-118
.
Go to step 2.
2 Is there any loose or foreign material on the
cartridge roll? Replace the print cartridge. Go to step 3.
3 Is there any loose or foreign material on the
transfer module? Replace the transfer
module. See
“Transfer
module removal” on
page 4-154
.
Contact your next level of
support.