Brother HL-1260 service manual All black, Completely blank

I-3

Completely blank

Possible cause	Step	Check	Result	Remedy
EP-ED cartridge	1	Does printed image improve when the EP-ED	Yes	Replace the EP-ED cartridge.
		cartridge is replaced?
Development	2	Do the pins 3, 4 and 5 of the connector?	No	Replace the main PCB assy
input signal		P6 on the main PCB have the following value		or the harness.
error		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.
Failure in power	3	Is there any dirt on the cartridge side	No	Clean the terminal to assure
supply terminal		development terminal of the transfer unit and		the continuity.
		on the terminal of the high-voltage power
		supply development unit? (is there continuity
		between them?)
LD failure	4	Does print quality improve when the scanner	Yes	Replace the scanner unit or
Failure in		unit is improved?		the harness.
development
			No	Replace the high-voltage
high-voltage circuit
				power supply PCB assy.

I-4

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Possible cause	Step	Check	Result	Remedy
Beam detection	1	Is the printer hung up with the PRINT message	Yes	Replace the scanner unit or
error		remaining on the display even after a printing		the harness.
		when only a copy is printed?
EP-ED cartridge	2	Does printed image improve when the EP-ED	Yes	Replace the EP-ED cartridge.
		cartridge is replaced?
Charging input	3	Do the pins 1 and 2 of the connector P6 on the	No	Replace the main PCB assy
signal error		main PCB have the following value respectively		or the harness.
		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.
Dirt on power	4	Is there any dirt on the cartridge side charging	No	Clean the contact to assure
supply terminal		terminal of the transfer unit and on the terminal of		the continuity
Failure in the		the high-voltage power supply charging unit?
		(is there continuity between them?)	Yes	Replace the high-voltage
charging high-
				power supply PCB assy and,
voltage circuit
				if the problem is not resolved,
LD failure				replace the scanner unit or
				the harness.

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