Troubleshooting Malfunctions - Brother HL1060 - B/W Laser Printer Service Manual

5.

TROUBLESHOOTING MALFUNCTIONS

When carrying out countermeasures for malfunctions as described in this section, check
connectors for contact failure before measuring the voltage at the specified connector pins.
M-1 No AC power supplied
Possible cause Step
Supply voltage
Power plug
Fuse (F1, F2)
Wiring
M-2 No DC power supplied
Possible cause Step
AC power supply
Wiring, DC load
Low-voltage
power supply
PCB
Caution: If you analyze malfunctions with the power plug inserted into the power outlet,
special caution should be exercised even if the power switch is OFF because it is
a single pole switch.
Check
1 Is the correct voltage present at
the outlet?
2 Is the power cord securely
plugged into the outlet?
3 is the fuse blown?
4 Unplug the power supply plug.
Is there a broken wire between
the AC input connector of the
low-voltage power supply and
the power plug?
Check
1 Is AC power supplied between
connectors CN1-L and CN1-N
when the power plug is plugged
into the outlet?
2 Turn the power switch OFF and
disconnect the P13 connector
(Driver PCB).
Turn the power switch ON
again. Measure the voltages
between the terminals.
Do the measured voltage
satisfy the prescribed value in
the table below?
PCB + lead pin - lead pin
Driver P13-4.5 P13-2.3
P13-8.9 P13-6.7
CHAPTER IV -22
Result
No Inform the user that the correct
voltage is not supplied at the
outlet.
No Plug the power cord securely
into the outlet.
Yes If the fuse blows again
immediately after replacing the
low-voltage power supply PCB,
check that there is not a short
circuit somewhere in the AC
power supply line.
Yes Replace the AC power cord.
Result
No Follow the same check
procedure of M-1 "No AC
power supplied".
Yes Turn the power switch OFF,
reconnect the connector and
turn the power switch ON
again.
If the protector circuit is
activated, check the connector,
the wiring from the connector,
and the DC load.
No Replace the low-voltage power
Voltage
supply PCB.
Approx. 24V
Approx. 5V
Remedy
Remedy