Canon CLBR 460ps Service Manual page 273

4) Defective rotary drive unit
Action: Replace the rotary drive unit if the developing bias contact of the rotary drive unit
does not operate normally.
5) Poor contact in connectors
Action: Check the wiring between the rotary drive unit, high-voltage PCB, and DC controller
PCB and reconnect the connectors correctly.
6) Defective high-voltage PCB (does not output the developing bias)
Action: Replace the high-voltage unit.
7) Defective DC controller PCB
Action: Replace the DC controller PCB.
[ 2-4 ] All black
<Possible causes>
1) Poor contact between the primary charging bias contacts of the drum cartridge and the print-
er.
Action: Clean the primary charging bias contacts of the drum cartridge 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.
2) Defective drum cartridge (primary charging roller)
Action: Replace the drum cartridge.
3) Poor contact in connectors
Action: Reconnect the connectors between the primary charging contact, high-voltage PCB,
and DC controller PCB correctly.
4) Defective high-voltage PCB (the primary charging bias is not output)
Action: Replace the high-voltage unit.
5) Defective DC controller PCB
Action: Replace the DC controller PCB.
[ 2-5 ] Dots in vertical lines
<Possible causes>
1) Dirty static charge eliminator
Action: Clean the eliminator.
2) Poor contact between the static eliminator contact of the printer and the static eliminator
Action: Clean the contacts if dirty. if the problem still remains after cleaning, or the con-
tacts are deformed or damaged, replace them.
3) Deformed or deteriorated transfer charging roller
Action: Replace the transfer charging roller.
CHAPTER 4
4 - 19