Canon GP405 Service Manual page 441

2 Shading Auto Correction
• Shading auto correction may be either of two types (CCD-ADJ, MAN-AJD). Select the
appropriate mode.
• In shading auto correction, various data measurements are taken and stored in the RAM on the
image processor PCB for use as the target value for shading correction performed before
scanning operation.
The following are service mode item related to shading auto correction; see the appropriate
service mode item for details:
ADJUST ADJ-XY
CCD
FUNCTION CCD
Using CCD-ADJ
• Start service mode.
1) Press the asterisk key.
2) Press '2' and '8' on the keypad at the same time.
3) Press the asterisk key.
4) On the screen, select <COPIER>, <FUNCTION>, and <CCD> in sequence.
5) Select <CCD-ADJ>, and press the OK key. (You need not place standard white paper.)
Using MAN-ADJ
1) Remove the rear cover, and check the position of VR200 on the DC controller PCB.
2) Place the standard white paper on the copyboard glass.
3) Start service mode. (See steps 1) through 4) under "Using CCD-ADJ.")
4) Select <MAN-ADJ>, and press the OK key.
5) When VO is indicated and the beep is sounded, press the OK key. If the beep is not heard, turn
VR200 on the DC controller PCB; when the beep is sounded, press the OK key. Adjustments
are needed if LED201 turns on.
6) Check to see if END is indicated.
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
ADJ-S standard white plate read position
PPR standard white paper density data
W-PLT standard white plate density data
CCD-ADJ shading auto correction 1 (for normal image adjustment)
MAN-ADJ shading auto correction 2 (for PCB, lamp replacement)
DC controller PCB
Figure 14-229
CHAPTER 14 TROUBLESHOOTING
VR200
LED201
14-23