Epson DFX-8500 Service Manual page 199

Symptom
The RF motor The parallelism value
does not operate. is incorrect.
The RF motor The RF motor is
does not operate. defective.
The PG motor The backlash value is
does not operate. incorrect.
The PG encoder
sensor is defective
The encoder plate is
defective.
The PG home sensor
is defective
The PG motor is
defective.
Printing continues The front, rear, or top
past the end of PE sensor is
the paper. defective.
When paper jams, The paper jam sensor
the printer does is defective.
not beep.
Ribbon Jam error Ribbon jam sensor is
occurs even the
defective.
ribbon is fed
correctly.
Rev. B
Table 5-7. Printer Mechanism Repair 3/4
Cause
Check whether the carriage moves
smoothly when moved manually.
(Check that foreign objects are not
lodged in the printer mechanism.)
Check the coil resistance of the RF
motor. (It should be about 150 ohms +
10 %.)
Check whether the carriage guide shaft
rotates smoothly when rotated
manually.
Check the output signal of the PG
encoder sensor. (Refer to Table 5-6.)
Check whether the encoder plate is
broken or stained.
Check the continuity of the sensor.
(Check the status of the two micro
switches.),
Check the coil resistance of the PG
motor. (It should be about 250 ohms +
18 ohms.)
Check the PE sensor.
Check the paper jam sensor.
Check the ribbon jam sensor.
Checkpoint
TROUBLESHOOTING
Solution
Perform the
parallelism
adjustment, as
described in Section
4.1.5.
Replace the RF
motor.
Loosen the 2 screws
securing the PG
motor to the left side
frame. Then adjust
the backlash
between the PG
motor pinion gear
and the carriage
guide shaft gear, as
described in Chapter
4, Adjustments .
Replace the PG
encoder sensor.
Replace the PG
motor or clean the
encoder plate.
Replace the PG
home sensor (micro
switch type).
Replace the PG
motor.
Replace the PE
sensor.
Replace the paper
jam sensor.
Replace the ribbon
jam sensor.
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