Repairing The Printer Mechanism - Epson FX 890 - B/W Dot-matrix Printer Service Manual

3.5 REPAIRING THE PRINTER MECHANISM

For detailed procedures for replacing or adjusting matter, refer to Chapter 4, Disassembly and
Assembly and Chapter 5, adjustments . If a problem or symptom occurs, refer to the following
tables and find out other potential causes.
Symptom
Problem: The CR motor fails to operate.
The CR motor fails to
drive the timing belt
after power on.
Problem: The carriage dose not operate at power on (after carriage has been manually
centered prior to power on).
The CR motor rotates,
but the carriage dose
not move.
The carriage moves to
the left slightly, then
stops.
The carriage moves to
the left or right end,
then stops.
Problem: Self test printing is not executed.
The carriage moves,
but dose not print.
Rev. B
Table 3-12. Repairing the Printer Mechanism
Cause
Foreign matter is
lodged in the
mechanism.
The CR motor is
defective.
The belt drive or
driven pulley is
defective.
The timing belt is
defective.
The carriage
movement is not
smooth.
The HP detector is
defective.
The printhead FFC
common wires are
disconnected.
The printhead is
defective.
FX-1180/FX-880 Service Manual
Chapter 3 Troubleshooting
Checkpoint
Manually move the
timing belt to see if the
motor can rotate freely.
Measure the motor coil
resistance. It should be
about 16 ohms. If the
coil is shorted, check CR
motor driver IC8 on the
main board.
Check the pulleys which
are broken or worn.
Check if the timing belt
is correctly set to the
carriage.
Check if the timing belt
is broken.
Check if the carriage
moves smoothly as you
move it manually.
Check the HP detector
using a multi meter.
Check whether FFC is
properly connected to
the printhead or the
main board.
Measure the printhead
coil resistance. It should
be about 8 ohms. If the
printhead is shorted,
check the drivers on the
main board.
Solution
Remove the
foreign substance.
Replace the CR
motor (and main
board, if
necessary).
Replace the
pulleys.
Reset the belt to
the carriage.
Replace the belt.
Clean and
lubricate the CR
guide shaft or
frame. Otherwise,
replace the CR
motor.
Replace the HP
detector.
Connect the FFC
to the printhead or
the main board
correctly.
Replace the
printhead, (and
drivers , if
necessary).
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