Panasonic TC-P50X5 no power no red light

[jbjsabu]

I am looking at a TC-P50X5 TV which went out after a nearby transformer blew. It was on aerial antenna. After setting for a few days it came back on. Then off again. The last time it worked for about two weeks and was unplugged and moved and now is off again.

On the power board, it has power on the hot side and no voltage on the cold side. There is output from the big bridge chip.

The STB5V and other marked test wires are 0V and there is no red light on the front lit up. This is also true when the other boards are unplugged from the power board. On the occasions when the red light comes on, the TV works.

I will try to insert a pic of the TV and power board:

http://s1117.photobucket.com/user/jb...50x51.jpg.html
http://s1117.photobucket.com/user/jb...50x52.jpg.html

I have searched other threads and haven't found anything real close.
Any help would be appreciated.

[jbjsabu]

Re: Panasonic TC-P50X5 no power no red light

About once every five or ten tries, STB5V comes on when power is applied (after having removed the power cord between tries). When that happens all the voltages are OK and the set comes on when POWER switch is pressed.

Any general or specific schematics of what the 5V standby circuit might look like or consist of?

[tom66]

Re: Panasonic TC-P50X5 no power no red light

I would try heating parts of the power board gently. See if you can invoke it to start up by heating parts up.

Very new TV, 2012. And very poorly built for Panasonic, they have gone down the drain to say the least with these new TVs.

[jbjsabu]

Re: Panasonic TC-P50X5 no power no red light

That does sound like a good idea. Unfortunately? the board has quit failing on me. Four days and several dozen Power on/off cycles and it continues to work fine. I also tried running some hot air across it to try to make it fail and no response there.

I guess that is sort of good news, but the problem is still unresolved, and I had just ordered a replacement P board

I guess I will give it a few more days and call it "good" and put the spare P board on ebay if it stays that way.

Thanks for the response.

[tw2005]

Re: Panasonic TC-P50X5 no power no red light

That does sound like a good idea. Unfortunately? the board has quit failing on me. Four days and several dozen Power on/off cycles and it continues to work fine. I also tried running some hot air across it to try to make it fail and no response there.

I guess that is sort of good news, but the problem is still unresolved, and I had just ordered a replacement P board

I guess I will give it a few more days and call it "good" and put the spare P board on ebay if it stays that way.

Thanks for the response.

possible solution I stumbled across.

Plasma tv Panasonic GPF15DE Chassis can cause not powering on & standby LED lit
can be very intermittent
.
At a certain sequence of events, the TV does not turn on
and the standby LED is not lit. For example, after disconnecting
of power, then after you turn
within 3 minutes. This modification applies to all
PSU with serial number earlier than below:
42” N0AE6JK00005 **-2550001
50” N0AE6JK00006 **-2560001

TCZAA6755U IC ref (U203)

Not 100% if datasheet is correct device or proprietary for Panasonic by Fairchild.

Does look like FAN6755UW going by the format in the sheet.

Translated some other info.

Some links for the IC

http://www.ebay.com.au/itm/PANASONIC...-/160971382674

http://www.ohmsupplies.co.uk/TCZAA67...42X50-TXP50X50

http://www.notobsolete.co.uk/index.p...oducts_id=1209

http://www.chsinteractive.co.uk/elec...-panasonic.htm

[jbjsabu]

Re: Panasonic TC-P50X5 no power no red light

That sure is a promising and good find. The TV owner has been using it for a month now and it has been working all right except for a one week stretch where it would not turn on.

I will ask him if he wants me to gamble with a possible solution. I don't suppose I could make it worse, although I have never unsoldered/re-soldered a surface mount component.

Thanks for the info!

[RJARRRPCGP]

Re: Panasonic TC-P50X5 no power no red light

That sure is a promising and good find. The TV owner has been using it for a month now and it has been working all right except for a one week stretch where it would not turn on.

Sounds like it may just be poor soldering on the power input end...

Sounds like my Uniden Bearcat scanner before reflowing the solder joints for the power input...

[tw2005]

Re: Panasonic TC-P50X5 no power no red light

That sure is a promising and good find. The TV owner has been using it for a month now and it has been working all right except for a one week stretch where it would not turn on.

I will ask him if he wants me to gamble with a possible solution. I don't suppose I could make it worse, although I have never unsoldered/re-soldered a surface mount component.

Thanks for the info!

Something that size is a piece of cake. If you had some fine cutters you may be able to snip the legs close to the body.

You could flow solder across the legs to heat them all at once to lift it. I've used 2 soldering irons to heat both sides at once and used the tips like tweezers to lift at the same time.

Good chance there be video somewhere to learn from.

[mark_]

Re: Panasonic TC-P50X5 no power no red light

Does anyone know if it's possible to bypass this component to test ?
On mine I have AC voltages on the HOT side but nothing on the COLD side.
They give lots on test points on the COLD side but none on the HOT.

[rbav006]

Re: Panasonic TC-P50X5 no power no red light

I am looking at a TC-P50X5 TV which went out after a nearby transformer blew. It was on aerial antenna. After setting for a few days it came back on. Then off again. The last time it worked for about two weeks and was unplugged and moved and now is off again.

On the power board, it has power on the hot side and no voltage on the cold side. There is output from the big bridge chip.

The STB5V and other marked test wires are 0V and there is no red light on the front lit up. This is also true when the other boards are unplugged from the power board. On the occasions when the red light comes on, the TV works.

I will try to insert a pic of the TV and power board:

http://s1117.photobucket.com/user/jb...50x51.jpg.html
http://s1117.photobucket.com/user/jb...50x52.jpg.html

I have searched other threads and haven't found anything real close.
Any help would be appreciated.

Have you had this issue resolved? If yes, please share how did you fix it?
I have exact same issue as you pointed with Panasonic TC-P50X5

[jbjsabu]

Re: Panasonic TC-P50X5 no power no red light

Hi,
I bought a power board off ebay for $45 and swapped it in.
It may have helped a little, but my buddy with the TV says it
still goes out every once in a while and he just watches his
little TV until the darn thing decides to come back on within
a day or two. Hope you have better luck.
Jeff

[BigPete]

Re: Panasonic TC-P50X5 no power no red light

Just in case this helps someone, I bought a TH-P42X50 with the same issue. Swapped out U203 with a NCP1271B, as that's what I could get at the time, but still didn't power up. Turns out D308 was shorted as well. It's a SS320 diode.