Mitsubishi Electric LC62 CHASSIS XL6500LU Service Manual page 9

Power source system 3
Remove the MAIN PCB ASSY and
connect the LAMP JIG.
Turn on [FAN-ON], and [LAMP-ON] of the
LAMP JIG.
Remove the RE-CN1 lead wire and
turn on [FAN-ON] of the LAMP JIG.
The terminal shield
secondary side are checked.
(Do not use a heat dissipation board as GND.)
When measuring the voltage on the primary side, use the negative (-) terminal of C903 as GND.
The lamp does not light.
Is the lead wire or
connector between the
POWER PCB ASSY and
LAMP POWER UNIT
OK?
YES
Does the lamp light?
NO
Is the voltage between
the pins No. 1 and No.
3 of the RE connector
370 V?
POWER PCB ASSY
NO
Is the voltage of the
pin No. 10 of IC9M0
17.5 V or more?
POWER PCB ASSY
YES
Malfunction of the PFC circuit.
Check the circuits around
IC9M0, Q900, Q901, and Q902.
can be used as GND when the terminal voltages and the waveforms on the
Connect the lead wires correctry,
NO
or replace them.
YES Malfunction of the the MAIN PCB ASSY.
Malfunction of the LAMP
YES
POWER UNIT.
Check the circuit around
NO
Z900, IC900, and PC901.
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