Canon CLBR 460ps Service Manual page 278

CHAPTER 4
Action: Reconnect J101 and J103 on the feed PCB and J1014 on the DC controller PCB
correctly.
16) Defective feed PCB
Action: Replace the feed PCB.
17) Defective DC controller PCB
Action: Replace the DC controller PCB.
[ 2-13 ] Blank spots
<Possible causes>
1) Defective photosensitive drum or primary charging roller
Action: Replace the drum cartridge.
2) Defective secondary transfer roller contact/separation drive cam and gear
Action: Replace any defective parts(s).
3) The intermediate transfer belt is deformed or contaminated with oil.
Action: Replace the ITB unit.
4) Poor contact in the secondary transfer bias contacts of the secondary transfer roller and the
printer
Action: Clean the secondary transfer bias contacts of the secondary transfer roller and the
printer. If the problem persists after cleaning, check the contacts and replace any
deformed or damaged part(s). If the contacts are slipped off, adjust them correctly.
5) Poor contact in connectors
Action: Reconnect the connectors between the high-voltage PCB and DC controller PCB cor-
rectly.
6) Defective high-voltage PCB (secondary transfer bias output shortage)
Action: Replace the high-voltage PCB.
7) Defective DC controller PCB
Action: Replace the DC controller PCB.
[ 2-14 ] Poor fixing
<Possible causes>
1) The nip width of the fixing unit is not within the specification.
Action: Replace the fixing unit.
2) Scarred or deformed upper fixing roller
Action: Replace the upper fixing roller.
3) Scarred or deformed lower fixing roller
Action: Replace the lower fixing roller.
4) Deterioration of upper and lower thermistors
Action: Replace the upper and lower thermistors.
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