FujiFilm CR-IR341 Service Manual page 448

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ONTENTS
(2) With reference to the examples of abnormal images described in this section, take
remedial action as appropriate in accordance with <Probable Causes> and <Check
and Reference>.
(3) Use the virtual image generation mode (quasi-reading) to analyze the cause of the
abnormal image.
Perform image reading by generating quasi-image signals from various portions of
the scanner. Based on the results of the virtual image generation mode, isolate the
cause of the abnormal image.
"10.10 Setting in Virtual Generation Mode for Image Signal" in Maintenance
Utility
Result of virtual image generation mode
No abnormal image occurs with "LIGHT".
An abnormal image occurs with "LIGHT",
but not with "LOG AMP".
An abnormal image occurs with "LIGHT"
and "LOG AMP", but not with
"SCN08 INPUT".
An abnormal image occurs with "LIGHT",
"LOG AMP", and "SCN08 INPUT".
009-051-07
08.30.2001 FM3115
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Isolation of problem
The cause of the problem is present
before the IP-generated light enters
the photomultiplier. (The IP-generated
light is already abnormal.)
The cause of the problem is present
between light admittance to the
photomultiplier and photomultiplier
current output (to the PMT board).
Alternatively, it is present in the high-
voltage applied to the photomultiplier.
The cause of the problem is present
between PMT board input and SCN
board input.
The cause of the problem is present
in the image signal lines after image
signal input for the SCN board.
CR-IR341 Service Manual
Probable cause
• Optics (including the laser)
• Light-collecting guide/light-collecting mirror
• Subscanning
• X-ray source
• IP
• Conveyors
• Erasure failure
• Extraneous noise to the laser, etc.
• Photomultiplier
• High-voltage power supply (located on the PMT
board)
• Erasure or extraneous leak light
• Optical noise due to electrostatic buildup on the IP
• Magnetic noise
• SCN08A board
• PMT board
• Extraneous electric noise to the PMT board
(static noise on the IP, power supply noise,
motor noise, etc.)
• Cables between PMT board and SCN board
• SCN08A board
• Extraneous electric noise to the SCN08A board
(electric noise, motor noise, etc.)
• Image-related boards after SCN08 (IMG board,
etc.)
• Cables to such boards
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TR1H1303.EPS
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