Lexmark T420, Service Manual

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2-52
Service Manual
4048–00x
Partial Blank Image/White Spots (no periodic pattern)
Variation in Image Density Horizontally Across Page
FRU Action
Toner Cartridge (not a FRU) Remove the toner cartridge and
gently shake the assembly to evenly
distribute the toner.
If the toner cartridge is low, try a new
one.
Fuser Backup Roll Springs
(not a FRU)
Fuser Assembly Check springs at each end of the
backup roller springs and backup
roller to ensure adequate and even
pressure is applied to the fuser hot
roll. Replace the fuser if necessary.
Paper Make sure recommended paper is
being used.
FRU Action
Toner Cartridge The charge roll may have an
unbalanced pressure against the PC
drum. Check for equal forces at both
ends of the charge roll.
Try a new toner cartridge.
Transfer (Roll)/Bearings
Transfer Assembly Roll Check the springs and bearings at
both ends of the transfer roller. The
bearing assemblies should support
the transfer roller, applying even
pressure to the PC drum.
Replace both bearing assemblies if
either spring shows signs of damage
or fatigue.
Inspect the transfer roller for signs of
wear or damage and replace as
necessary.