I got a HITACHI Plasma TV
42PD5000 for 6 years.
Now, its totally dead, no picture, no sound, no red nor green LED on.
Here are the findings & action taken:-
a. 3A mains fuse blown - replaced.
b. Resistor R004 & R005 10 ohm 5w open - replaced.
c. FET 2SK2843 shorted - replaced.
1.Stby red LED on, use remote can turn the green LED on only, no picture.
2.Stby 5v & Stby 3.3v availiable,
3.No 5v, 12v, 30v found at CNPPS, nor VA & VS volt.
4.Relay RL001 & RL002 first energized, then de-energized.
Further measurement & action:-
a. Unplug CNPPS & CN69, direct linked Stby 5v to CNPPS pin 4,5 (5v).
Result:- same -Stby red LED on, use remote can turn the green LED on only, no picture.
Relay RL001 & RL002 first energized, then de-energized
I understand the protection circuit activaties the 2 relays which cut off the mains supply to switching circuit hence the whole TV stop working.
However, i couldn't locate further defects though i have checked for bulgeing caps, shorted diodes, shorted FETs, shorted photo couplers....
Kindly,if you could help me to explore further & solve the problem!