Epson DFX-8500 Service Manual page 197

5.2.3 Printer Mechanism Repair
The table below describes how to isolate problems with the printer mechanism. To replace or adjust printer
mechanism parts, refer to Chapter 3, Disassembly and Assembly , and Chapter 4, Adjustments .
symptom recurs following a repair attempt, look for other possible causes and solutions in the table below.
Symptom
The CR motor The transport locking
does not operate. bracket (used to hold
the carriage in place
when the printer is
moved) has not been
removed.
Foreign objects are
lodged in the gears or
elsewhere (e.g. paper
dust on the carriage
encoder belt) in the
mechanism.
The CR motor is
defective.
The carriage timing
belt is defective.
The carriage guide
shaft parallelism
value is incorrect.
The CR encoder
sensor is defective.
The carriage encoder
belt is damaged or
covered with dust.
The carriage The printhead FPC
moves, but no common wires are
printing is broken.
performed.
Rev. B
Table 5-7. Printer Mechanism Repair 1/4
Cause
Verify that the transport locking bracket
has been removed.
Manually move the carriage to see if
the motor rotates.
Measure the coil resistance of the CR
motor. It should be approximately 1.66
ohms + 10 %.
Manually check the carriage timing belt
tension.
Check whether the carriage moves
smoothly when moved manually.
(Check that foreign objects are not
lodged in the printer mechanism.),
Check the waveform for the carriage
encoder signal. (Refer to Table 5-6.),
Check the encoder belt (below the
carriage timing belt).
Check the continuity of the common
wires for the printhead FPC.
Checkpoint
TROUBLESHOOTING
If a
Solution
Remove bracket.
(Refer to Section
3.1.)
Remove any foreign
objects.
Replace the CR
motor.
Perform the carriage
timing belt tension
adjustment, as
described in Section
4.1.2.
Perform the carriage
guide shaft
parallelism
adjustment, as
described in Section
4.1.5.
Replace the CR
encoder sensor.
Replace or clean the
carriage encoder
belt.
Replace the FPC.
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