Brother HL-1260 - Manual (Page 82)

VI - 5
10 No Development
input signal error 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. Replace the scanner unit or
the harness.
Possible cause Step Check Result Remedy
Dirt on power
supply terminal
Failure in the
development
high-voltage
circuit
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?) 11 No Clean the contacts to assure
the continuity.
Yes Replace the high-voltage
power supply PCB assy.
1 Yes Density setting Does printed image improve when density
setting is changed on the control panel? Adjust the proper setting on
the control panel.
I-2 Dark
Possible cause Step Check Result Remedy
EP-ED cartridge
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?) 5 No Clean the terminal to assure
the continuity.
Yes Replace the high-voltage
power supply PCB assy.
2 Does printed image improve when the EP-ED
cartridge is replaced? Yes Replace the EP-ED cartridge.
Dirt on the
grounding
terminal 3 Does printed image improve when continuity
is improved by cleaning the EP-ED cartridge
grounding terminal and the printer unit
grounding terminal? Yes Clean the contacts to assure
the continuity.
Charging input
signal error 4 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. No Replace the main PCB assy
or the harness.
Dirt on power
supply terminal
Failure in the
charging high-
voltage circuit