Lexmark 2480 - Forms Printer B/W Dot-matrix, Service Manual

Page: 47 / 170

Diagnostic Information
2-29
24xx
Printhead Service Check
FRU Action
1 Printhead Cables
Printhead If the printout contains missing or extra dots or
lines, do the following:
• Check the continuity and connection of the
printhead cables and the short flexible cable.
• Be sure the voltages to the logic board are
correct.
If dots are missing:
• Perform the print test to determine which
wire is not firing.
• Remove the printhead and verify that no
pins on the printhead are broken or missing.
If pin(s) are missing, replace the printhead.
• Check the printhead resistance according to
“Printhead Impedance Tables” on
page 2-30
. Be sure no pins have continuity
to the printhead housing.
If the printout does not contain missing or extra
dots or lines, be sure the printhead is securely
installed in the carrier and perform the
“Printhead-to-Platen Gap Adjustment” on
page 4-2
.
2 Carrier Shaft
Carrier Unit
Platen Assembly
Printhead Nose
Ribbon Guide Check and replace worn or damaged parts.