Epson Stylus Pro 4910 Service Manual page 293

Epson Stylus Pro 4900/Epson Stylus Pro 4910
Class Adjustment Items
1
PF Belt Adjustment
PF Encoder and Scale
2
Check
Media Feed
4
Related
Paper Thickness Sensor
3
Position Adjustment
4
Rear AD Adjustment
ADJUSTMENT
General Overview
Give a specified tension to the PF timing belt. Measure the
tension using the Sonic Tension Meter U-507 to check if it
is within the standard value. If it is not within the standard
value, adjust the tension.
Confirm that the PF Scale does not have any abnormality
such as damage or dirt and the encoder can read properly
using the Service Program.
Adjust the sensor installation position so that the Paper
Thickness Sensor can detect the paper thickness
accurately. Execute this adjustment with the paper
thickness adjustment jig.
Adjust the detection sensitivity of the Rear Sensor so that it
can recognize the paper inserted in the printer correctly.
Let the sensor detect the translucent media which is hard to
recognize to check the result on the Control Panel. (By
using the media which is hard to recognize, paper can be
recognized regardless of the environmental condition or
the media)
Overview
Symptom
When the tension is out of the standard value,
the following symptoms may occur.
Belt tension is high:
The life of the belt will be shortened.
The load gets higher, and the PF
operation gets Wait control by the
heating control.
If the tension is too high, the shaft of the
motor leans and the brush in the motor is
worn. This will cause the CR overload
error (SC112A).
Belt tension is low:
Slipping of the teeth of the belt occurs
and paper feeding cannot be executed
correctly.
The PF Scale cannot be read correctly, the paper
feeding does not operate, and an error occurs.
If the adjustment is not executed, the paper
thickness is not detected properly. As the result,
the PG is not set correctly responding to the
thickness of paper which is actually inserted in
the printer.
PG gets wider:
Low print quality caused by such as the
difference of spotted ink locations and flow
curve
PG gets narrower:
Head rubbing
If the adjustment is not executed, paper
recognition failures may occur (e.g. paper empty
error occurs even with paper inserted, some
media are not recognized).
Revision A
Tool
Page
SP SM MECH
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294
Confidential