Brother HL 2060 - B/W Laser Printer Service Manual page 87

Possible cause Step
Development 10
input signal
error
Dirt on power 11
supply terminal
Failure in the
development
high-voltage
circuit
I-2 Dark
Possible cause Step
Density setting 1
EP-ED HC 2
cartridge
Dirt on the 3
grounding
terminal
Charging input 4
signal error
Dirt on power 5
supply terminal
Failure in the
charging high-
voltage circuit
Check
Do the pins 3, 4 and 5 of the connector
P6 on the main PCB have the following value
respectively when a sheet of paper is fed from
the MP tray?
P6-3 pin (DBAC) --- Change in voltage from
6V approx. to 0V just when a sheet of paper is
fed from the registration unit.
P6-4 pin (DBDC) --- Change in voltage from
9V approx. to 0V just when a sheet of paper is
fed from the registration unit.
P6-5 pin (DNSTY) --- Change in voltage to
2.5V just when a sheet of paper is fed.
Is there any dirt on the cartridge side
development terminal of the transfer unit and
on the terminal of the high-voltage power
supply development unit? (is there continuity
between them?)
Check
Does printed image improve when density
setting is changed on the control panel?
Does printed image improve when the EP-ED
HC cartridge is replaced?
Does printed image improve when continuity
is improved by cleaning the EP-ED HC
cartridge grounding terminal and the printer
unit grounding terminal?
Do the pins 1, 2 and 5 of the connector P6
on the main PCB have the following value
respectively when a sheet of paper is fed from
the MP tray?
P6-1 pin (HV1AC) --- Change in voltage from
6V approx. to 0V just when a sheet of paper is
fed.
P6-2 pin (HV1DC) --- Change in voltage from
9V approx. to 0V just when a sheet of paper is
fed.
P6-5 pin (DNSTY) --- Change in voltage to
2.5V just when a sheet of paper is fed.
Is there any dirt on the cartridge side charging
terminal of the transfer unit and on the terminal
of the high-voltage power supply charging unit?
(is there continuity between them?)
Result
Result
VI-5
Remedy
No Replace the laser unit or
the harness.
No Clean the contacts to
assure the continuity.
Yes Replace the high-voltage
power supply PCB assy.
Remedy
Yes Adjust the proper setting
on the control panel.
Yes Replace the EP-ED HC
cartridge.
Yes Clean the contacts to
assure the continuity.
No Replace the main PCB
assy or the harness.
No Clean the terminal to
assure the continuity.
Yes Replace the high-voltage
power supply PCB assy.