
MLT-288 Service Manual
18
4-2 Guide to Repair
4-2-1 Guide to repair
1/2
Cause
Power supply to head poor.
Thermal head connection
poor.
Thermal head assembly
poor.
Power supply to head poor.
Thermal head assemble
poor.
Foreign matters stuck on
thermal head.
Thermal head assembly
poor
Power supply to head poor.
Dirt stuck on thermal head
Paper poor
Check method
Measure power supply voltage
with tester or oscilloscope.
Check connected condition of
connector.
—
Measure power supply voltage
with tester or oscilloscope.
—
Check if foreign matters stuck
on thermal head.
—
Measure power supply voltage
with tester or oscilloscope.
Check if dirt stuck on thermal
head.
Check if paper that meets
specification is used.
Repair method
If out of rating, correct
power supply circuit.
Connect connector
correctly.
Replace thermal head
assembly.
If out of rating, correct
power supply circuit.
Replace thermal head
assembly.
Wipe foreign matters off
with soft cloth soaked in
ethanol.
Replace thermal head
assembly.
If out of rating, correct
power supply circuit.
Wipe dirt with soft cloth
soaked in ethanol
Replace paper that meets
specification.
Phenomenon
Print impossible
Print Light-
colored
Dots missing
Print very dirty
Print
quality poor
Print
Trouble