Epson LX-300 Service Manual page 91

Troubleshooting
Table 5-9. Repairing the Printer Mechanism (Continued)
Symptom
Problem
A particular
dot is missing. is defective.
Self-test
The printing is is cfef=ti'Je"
too light, or
the print
density is not
uniform.
Printing is per- The PF motor
formed but the assembly is
Paper feed is
abnormal.
fed or is not
fed uniformly.
The ribbon
The ribbon is
feed is
not turning.
abnormal.
5-14
Check Point
Cause
Measure the printhead coil
resistance. It should be
approximately 33.3 ohms. If
The printhead
the
check the drivers.
Check to see if the dot wires
are worn.
The printhead Check whether the tips of the
wires are worn.
Set the gap adjustment lever to Adjust the
The platen
the first position, and check the gap. Refer to
platen gap.
The appropriate value is 0.45
adjusted.
mm.
Foreign
substances Perform a visual cheek of the
are lodged in paper path.
the paper path.
Check that no foreign
substance is lodged between
not driving the the gears and that the gears
gear correctly. are not broken or worn.
Measure the coil resistance for Replace the
The PF motor the PF motor assembly. The
assembly is approximate value should be
defective. 56 ohms. If the motor is
shorted, also check the drivers . necessary).
Remove the ribbon cartridge,
The ribbon
rotate its knob manually, and
cartridge is
see if the ribbon feeds
defective.
normally.
Foreign
Check whether the RD ratchet
substances
rotates when the carriage is
are caught in
moved manually.
the gears.
LX-300 Service Manual
Solution
Replace the
drivers, if
shorted, ak)
is
necessary).
Replace the
Replace the
Section 4.1.1,
Platen Gap
Adjustment.
Remove any
foreign
substances.
Remove any
foreign
substances.
PF motor
assembly
reduction
gears.
Replace the
paper pickup
gears.
PF motor
assembly
(and drivers, if
Replace the
ribbon
cartridge.
Remove any
foreign
Replace the
ribbon feed
mechanism.