Hitachi P50H4011

[kgavionics]

HI
Someone gave me away a Hitachi P50H4011 plasma tv which has a problem.The tv doesnt power on by remote.the only way to turn it on is with an overide button hidden in the buttom of the tv.when i push on the button (physical button with a spring) the tv comes on and all i can see is snowy picture ( static) no menu or whatsoever.
i took the tv apart and i saw to bodging caps 3300 uF( the two big caps on the right hand side of the power supply),before i measure any voltage i tried to check their capacitance and ESR, so took them out and i found their value is around 2800 uF ( within the 10% of tolerance ) also the ESR was good around 0.11ohm.( i used a cheap chinese component tester to measure the ESR).
Because i don't have these capacitor value i tried to solder them back and measured all the voltages and i was surprise to find them all without any problem,but the power supply stop working for 5 seconds ( voltages become zeo and picture becomes black) and the cycle repeats.
i checked all the diodes, mosfet's and they seems to be good.beside the power supply intermittent problem, i'm wondering why i have the snowy picture, but no menu on the tv.
can someone tell me came across to this type of problem.

[dskall]

Re: Hitachi P50H4011

I would be replacing the two caps. I would think the button is override to ignore trouble codes. So you are forcing it on in spite of problems

[attainteddragon]

Re: Hitachi P50H4011

not sure if these can jumped on with the test patterns with the control board, but that would let you know if all of the other boards are working correctly.

if you post a pic of the control board, someone will be able to tell you if it can be done.

[kgavionics]

Re: Hitachi P50H4011

I have uploaded the service manual in zip format in case if someone want to take a look at it.

[Andrew F. Ali]

Re: Hitachi P50H4011

That appears to be a Main Bd problem to me.

[kgavionics]

Re: Hitachi P50H4011

Hi guys
I took a little break from this TV, i decided to fix it.I plugged the tv and it powers on like usual with the snowy picture.I tried to check the if there's any signal in the PDP module ( see first PDF attached), when i put the oscilloscope probe on the main IC chip, all of the sudden i lost picture and all the voltages on power board.I didn't see any burn or spark on the chip. I lost all the voltages on the power supply expect the 5V and 3.3V stbty voltages.Today i received the two big 3300uF 100V caps.replaced them.No luck the same problem discribed above.
I took out the power board and checked it and nothing seems wrong ( Diodes, Mosfets..)
I tried to follow the troubleshooting flow chart ( see pdf 2).
this is the voltages i found on the CN68 connector:
Pin1-5.3V
Pin2-0V
Pin3-3.3V
Pin4-0V
Pin5-0V
Pin6-5V-----Power1
Pin7-0V----Power2
Pin8-NC
they say if Power1 is high---the 5V output the CNPPS connector should go on.( in my case all theCNPPS connector is showing 0V).
if Power2 is high he 10V output the CNPPS connector should go on.in my case power2 is always 0.
According to the troubleshooting note, they say if either power1 or power2 is low, you may check the Main digital PWD.
I'm leaning toward the Main Digital PWD, but i want to know what do you think guys?