Toshiba 42HP83 Service Manual page 19

NO POWER ON
Relay sounds?
YES
Relay is turned OFF
immediatly after the
Relay is ON.
YES
Make a check by
disconnecting the processed
cable of CN805, 806,807.
NG
Make a check by
disconnecting the processed
cable of P809.
NG
Make a check by
disconnecting the processed
cable of P808.
NG
LOWB1 Unit side or Load side is abnormal.
Check Q835 and peripherals: Check the overvoltage and
overcurrent of 5V-2
Check Q829 and peripherals: Check the overvoltage and
overcurrent of 9V
Check Q820A and peripherals: Check the overcurrent of 3.3VA
Check the Load side of 12 V-line and 32 V-line
Check other SIGNAL Circuit side
Note: When PTF-422 is broken down, replace the whole POWER Unit. (Never repair the inside of PTF-422.)
NO
Check 5V-1.
Check the #9 of P807 by
disconnecting M807.
POWER_TV is HIGH
after connecting the M807
again?
POWER is operated
NO
normally.
Check other signal circuits.
PDP Panel Module is abnormal.
OK
Check the Panel and
peripherals.
Sound Output Circuit and
OK
peripherals are abnormal.
Check the Sound Output and
peripherals.
LOWB2 Unit side or Load side is abnormal.
OK
Check Q870 and peripherals: Check the overvoltage and
overcurrent of 3.3VS.
Check Q880 and peripherals: Check the overcurrent of 9VS
Connect the processed cable of P808, and disconnect the
processed cable of P808A to make a check again. If OK, check
the Scaler Unit side.
– 19 –
NO
Replace PFT-422.
Check the Microcontroller,
NO
Light Receiving Unit and
peripherals.
Check Q819, D819 and
peripherals of LOWB1.
YES
Replace PFT-422.