Mitsubishi SL1U Service Manual page 37

Power source system 4
Remove the PCB-MAIN and
connect the PCB-POWER
TEST.
Malfunction of PFC circuit.
Check the circuit around IC901
and Q900.
When measuring the voltage of the primary power source, use (-) terminal of C903 for GND.
The lamp does not light.
Are RE-CN1 and SA-
CN2 lead wires OK?
YES
Is the lamp lit?
NO
Pull out the RE-CN1 lead
wire. Turn on only FAN
and POWER on the PCB-
POWER TEST.
Are the pins No. 1
to 4 of the RE
connector 390V?
NO
Is the voltage of
the pin No. 8 of
IC901 20V?
YES
NO Insert or replace them.
Turn on FAN and LAMP on
the PCB-POWER TEST.
YES Malfunction of the PCB-MAIN.
Malfunction of LAMP
YES
POWER UNIT.
Check the circuit around
NO Z900, Q901, Q902, IC902
and PC901.
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