KPOWERSCIENCE KP3828 Series, Maintenance Manual

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8-12
[1E Fusing power supply failure]
Procedure Points to be checked Remedy Checking method
1 Is the fuser unit set
properly (is the
high-voltage
connection electrode
normal)? If YES, go to 3.
If NO, set the fuser
unit properly.
2 Is the fusing power
supply overheated? If NO, go to 3.
If YES, let the
power supply cool
for a while with the
power on.
3 Is there a fault in the
fusing power supply? If NO, go to 4.
If YES, set the
fusing power
supply voltage to
1850 V.
4 Is the KMPU board
normal? If YES, go to 5.
If NO, replace the
KMPU board after
checking the
harness.
Bring the positive lead of a digital
multimeter in contact with pin 7 of
CN3 of the KMPU board and the
negative lead in contact with SG (pin
8). Remove the jack from J11 of the
fusing power supply and short pins 7
and 8 of the jack. Turn on the power
in this condition and measure the
voltage. If normal, the voltage will be
approximately 0 V.
However, if a fusing power supply
error message is displayed even though
the voltage measured above is
approximately 0 V, replace the KMPU
board.
5 Is there a fault in the
fusing power supply? If YES, replace the
fusing power
supply. Connect the jack to J11 of the fusing
power supply.
Bring the positive lead of a digital
multimeter in contact with pin 7 of
CN3 of the KMPU board and the
negative lead in contact with SG (pin
8).
Then turn on the power and measure
the voltage in the condition where the
alarm indication LED is not lit.
If normal, the voltage will be
approximately 0 V.