Brother FAX-2820 Service Manual page 212

I-3 Completely blank
Possible cause
Step
Developing 1
bias contact
failure
Drum unit 2
Drum unit 3
failure
Toner 4
cartridge
failure
LD harness 5
connection
failure
Main PCB 6
failure
Laser unit 7
failure
Check
Are the developing bias
contacts between the printer
body and drum unit dirty?
Are the drum shaft and
drum electrode of the
printer body connected
correctly?
Is the problem solved after
replacing the drum unit?
Is the problem solved after
replacing the toner
cartridge?
Is the LD harness
connected securely?
(Check if there is any play
in the connection.)
Are printing signals being
input to the laser unit?
Is the problem solved after
replacing the main PCB?
Is the scanner interlock
lever damaged?
Is the scanner mirror
broken or loose?
9 - 3 1
Remedy
Result
Yes Clean the electrodes at
both sides.
Yes Clean the shaft and the
electrode.
No Check the connection
between the shaft and
the electrode.
Yes Replace the drum unit.
Yes Replace the toner
cartridge with a new
one.
No Reconnect the connector
correctly.
Yes Replace the main PCB.
Yes Replace the laser unit.
No Replace the high-
voltage power supply
PCB.
Laser scanner unit ASSY
Interlock lever
Ground
contacts
(4)
(1)
(1)
Confidential