Lexmark C734 Service Manual page 166

5026
Step Questions / actions
6 Turn off the printer and check the continuity of
the HVPS cable.
Pin 24
Pin 2
Is there continuity?
7 Replace the HVPS. See
power supply (HVPS) removal" on
page 4-94.
Did this fix the problem?
8 Replace the printhead. See
removal, installation, and adjustment" on
page 4-121.
Did this fix the problem?
Print quality—blurred or fuzzy print
Blurred or fuzzy print is usually caused by a problem in the EP drive assembly or in the transfer module. Check
the EP drive assembly and transfer module for correct operation.
Blurred print can also be caused by incorrect feeding from one of the input paper sources, paper trays, or duplex
paper path.
Check the high voltage spring contacts to ensure they are not bent, corroded, or damaged. Replace as
necessary.
Print quality—half-color page
A photoconductor unit is not properly seated. Reset the specific photoconductor unit.
Print quality—horizontal banding
Step Questions / actions
1 Measure the distance between repeating
bands.
Is the distance between bands either 27 or
36mm?
2-132
Service Manual
Pin 1
Pin 23
Pin 2
Pin 1
"High-voltage
"Printhead
Yes
Go to step 7.
Pin 23
Pin 24
Problem solved.
Problem solved.
Yes
Replace the print cartridge.
No
Replace the cable
assembly.
Go to step 8.
Replace the system board.
See "System board
removal" on page 4-139.
No
Replace the
photoconductor unit. See
"Photoconductor unit
removal" on page 4-118.