Troubleshooting - Epson Perfection 4490 photo Service Manual

EPSON Perfection 4490 Photo

3.2 Troubleshooting

This section provides troubleshooting procedures based on observed faults.
Refer to Table 3-4, and choose the table describes the general fault indication. Within
the table, find the Problem that most closely matches what you observe and follow the
procedures given in the table cross referenced in the right-hand column.
Table 3-4. Trouble Phenomenon, Cause and Troubleshooting Table
Problem
Scanned image quality error. Scanned image is not clear.
The main unit does not operate The Main Unit does not perform
when powered-on. initialization operation.
The host does not recognize the
scanner when power is switched on.
Fatal error. (The LED flashes red.) The Carriage Unit does not operate.
Recovery cannot be made when
The Fluorescent Lamps are not lit.
power is switched on again.
The TPU does not work at all. The TPU does not operate.
The TPU Carriage Unit does not
operate.
The Fluorescent Lamps of the TPU do
not light up.
TROUBLESHOOTING
Troubleshooting
Definition
Table
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3-12
Troubleshooting
Table 3-5. Scanned Image Quality Error.
Step Possible Cause
The Document Glass is not clean. (Image
1
has white spots)
The mirror in the Carriage is not clean.
2
(Vertical bands appear on the image.)
Upper Housing failure
3 (The white document mat is deformed or is
not clean.)
4 CCD Sensor Board failure
5 Main Board failure
6 Carriage mechanism failure
Table 3-6. The Main Unit does not perform initialization operation.
Step Possible Cause
There are some connectors that are not
1
connected correctly
2 CR Motor failure
3 Main Board failure
Table 3-7. The host does not recognize the scanner when power is switched on.
Step Possible Cause
1 The host computer does not support USB.
The TWAIN Driver supplied with the
2
scanner has not been installed correctly.
3 The USB cable is damaged.
4 Main Board failure
Revision B
Corrective Action
Clean the glass.
6.1.1 Cleaning
(Refer to )
Clean the mirror.
6.1.1 Cleaning
(Refer to )
Replace the Upper Housing.
Replace the Carriage Unit.
Replace the Main Board
Replace the Carriage mechanism.
Corrective Action
Connect them correctly.
Replace the Main Board
Replace the CR Motor.
Replace the Main Board
Corrective Action
Replace or modify the host computer.
Install (reinstall) the TWAIN Driver for the
Perfection 4490 Photo.
Replace the USB cable.
Replace the Main Board
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