Troubleshooting Of Malfunctions - Brother HL-730Plus Service Manual

3.

TROUBLESHOOTING OF MALFUNCTIONS

Always turn off the power switch and unplug the power cord from the power outlet before
accessing any parts inside the printer.
In case that you analyze malfunctions with the plug inserted into the outlet, such as
checking the supply voltage, special caution should be exercised even if the power
switch is OFF because it is one way off type. Touching the power supply PCB may
cause to struck you by electricity.
When carrying out the countermeasures for malfunctions described in this section, make
sure to check connectors for contact failure before measuring the voltage at specified
connector pins.
M-1 No AC power supplied
Possible cause Step
Supply voltage 1
Power plug 2
Fuse (F1) 3
Wiring 4
Check
Is the correct voltage present at the
outlet?
Is the power cord securely plugged
into the outlet?
Is the fuse blown?
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?


Result Remedy
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 low-voltage
power supply PCB.
Check if there is a
short circuit
somewhere in the AC
power supply line.
Yes Replace the AC power
cord.