Brother HL-1260 service manual Dark

Possible cause	Step	Check	Result	Remedy
Development	10	Do the pins 3, 4 and 5 of the connector	No	Replace the scanner unit or
input signal error		P6 on the main PCB have the following value		the harness.
		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.
Dirt on power	11	Is there any dirt on the cartridge side	No	Clean the contacts to assure
supply terminal		development terminal of the transfer unit and		the continuity.
		on the terminal of the high-voltage power
Failure in the		supply development unit? (is there continuity
			Yes	Replace the high-voltage
development		between them?)
high-voltage				power supply PCB assy.
circuit

I-2

Dark

Possible cause	Step	Check	Result	Remedy
Density setting	1	Does printed image improve when density	Yes	Adjust the proper setting on
		setting is changed on the control panel?		the control panel.
EP-ED cartridge	2	Does printed image improve when the EP-ED	Yes	Replace the EP-ED cartridge.
		cartridge is replaced?
Dirt on the	3	Does printed image improve when continuity	Yes	Clean the contacts to assure
grounding		is improved by cleaning the EP-ED cartridge		the continuity.
terminal		grounding terminal and the printer unit
		grounding terminal?
Charging input	4	Do the pins 1, 2 and 5 of the connector P6	No	Replace the main PCB assy
signal error		on the main PCB have the following value		or the harness.
		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.
Dirt on power	5	Is there any dirt on the cartridge side charging	No	Clean the terminal to assure
supply terminal		terminal of the transfer unit and on the terminal		the continuity.
		of the high-voltage power supply charging unit?
				Replace the high-voltage
Failure in the		(is there continuity between them?)	Yes
charging high-				power supply PCB assy.
voltage circuit

VI - 5