panasonic TX-P50C3B, wont turn on

[finntricky]

just picked this up, it has the green led flashing very fast, think i counted 5 maybe 6 before going out, there is no red standby light,
now i need to know where to start with this, as this is my first panasonic,
can't wait to get the back off this and have a look,

[tom66]

Re: panasonic TX-P50C3B, wont turn on

SN/SS shorts are possible and will cause set to lock out without fault code on these 2011 Panny's. I believe SS fails frequently but is an easy fix.

[finntricky]

Re: panasonic TX-P50C3B, wont turn on

SN/SS ?. sustain boards?, left and right.not Y and X
i'll get the back off later when i finish work

[tom66]

Re: panasonic TX-P50C3B, wont turn on

Yes, SN = Y-sustain+Y-buffer, SS = Z-sustain (SC=Y-sustain, no Y-buffer, but I think this set uses SN/SS...)

[finntricky]

Re: panasonic TX-P50C3B, wont turn on

here's some pics, got SN out and can't find a short, also SS and can't find a short, unless im doing it wrong, tryed on ohms and beep modes,

[finntricky]

Re: panasonic TX-P50C3B, wont turn on

have'nt got a clue what im doing here, tyred to disconnect boards one at a time, to try and find the faulty board but these don't seem to work like that, give me a sammy anyday, lol.
cant get any voltage reading in the split secound its on, just a quick jump and then falls,
seriously need some help here.

[newtothis]

Re: panasonic TX-P50C3B, wont turn on

my browser is having a fit with showing images atm,

Its a TX so probably same format as a few I have here.

On OHMs check the 2 pin power input on SN, What reading do you get?

[finntricky]

Re: panasonic TX-P50C3B, wont turn on

ok, finally got round to getting this out again,
in answer to your question,
i set DMM on 2000 ohms and got a steady reading of 620, this is the same with all wires and ribbons disconected as well,
also tryed an auto range meter but had no luck with any steady reading, it just keeps climbing and dropping.

[tw2005]

Re: panasonic TX-P50C3B, wont turn on

try this. disconnect sn2,ss11, p35, and the 3 white ribbons on the A board.

then try turning it on and observe the front led . don't do it for more than 30secs. then remove power and let it sit for 5,don't reconnect any leads

post the result

[finntricky]

Re: panasonic TX-P50C3B, wont turn on

sn 2 = power to sn board
ss11 = power to ss board
plus p35 to c board removed and ribbons from a board
result
no lights, no nothink,
what should i have seen ?

[finntricky]

Re: panasonic TX-P50C3B, wont turn on

forget what i just said,
just put all connections back and have the same result, no lights, no power, so now i have a power board prob, lol

[Alastair E]

Re: panasonic TX-P50C3B, wont turn on

ok, finally got round to getting this out again,
in answer to your question,
i set DMM on 2000 ohms and got a steady reading of 620, this is the same with all wires and ribbons disconected as well,
also tryed an auto range meter but had no luck with any steady reading, it just keeps climbing and dropping.

Check the IGBT's and diodes on both SN and SS Boards for shorts....

[finntricky]

Re: panasonic TX-P50C3B, wont turn on

power supply now sorted,
results of unplug test is the same as it was, green LED flashing fast 5 to 6 times before going off,
now im back to that stage, ill take the sn and ss out see what i can find
is it best to use diode mode or ohms mode for testing IGBT's

[tom66]

Re: panasonic TX-P50C3B, wont turn on

Diode mode works better. Although a short will show up on either....

[tw2005]

Re: panasonic TX-P50C3B, wont turn on

sn 2 = power to sn board
ss11 = power to ss board
plus p35 to c board removed and ribbons from a board
result
no lights, no nothink,
what should i have seen ?

I was hoping with both those boards disconnected and the ribbons removed it would turn on and stay solid green.

In your later post you said you tried the unplug test and same result so if that means you retried my suggestion and it did the same fast binking green then that makes me suspicious of the A or p board.

sure is a strange fault symptom you have

[finntricky]

Re: panasonic TX-P50C3B, wont turn on

I was hoping with both those boards disconnected and the ribbons removed it would turn on and stay solid green.

In your later post you said you tried the unplug test and same result so if that means you retried my suggestion and it did the same fast binking green then that makes me suspicious of the A or p board.

sure is a strange fault symptom you have

yep still the same as when i first git the tv, blinking green light very fast, maybe 5 or 6 blinks

[tw2005]

Re: panasonic TX-P50C3B, wont turn on

yep still the same as when i first git the tv, blinking green light very fast, maybe 5 or 6 blinks

Well, I'd be interested in input from the other guys but doing that it's only the A & P boards in play and it's neither staying on or generating an error blink. I'm leaning towards A board but not sure other than backprobing voltages as you turn it on to prove the p board is ok.

And from what you've said you have not found any shorts on the SN or SS but even if that was the issue a change in result should have been seen if they were having an affect on things.

This is a flow chart I was looking at which seems to describe your scenario. X30 will be the same design essentially as X3 i.e. HD TV 720P

last check would be checking the p board with ss/sn removed for short on P2 vsus.


Hard to know what this result means, really depends on how good the meters are. The first result could be wrong due to incorrect range, the second is most likely the cct charging. try reversing the probes but usually i see 100's K ohms on first probe and when re-probed to 2-3 meg ohms.


ok, finally got round to getting this out again,
in answer to your question,
i set DMM on 2000 ohms and got a steady reading of 620, this is the same with all wires and ribbons disconected as well,
also tryed an auto range meter but had no luck with any steady reading, it just keeps climbing and dropping.

[tom66]

Re: panasonic TX-P50C3B, wont turn on

Tw, on my U30B (2011 like this) a disconnected SN would lead to lit up LED but no picture. Connected but shorted SN meant dark green led. I didn't get a blink code in either case. It would flash a few times green before staying lit or dark

[tw2005]

Re: panasonic TX-P50C3B, wont turn on

Tw, on my U30B (2011 like this) a disconnected SN would lead to lit up LED but no picture. Connected but shorted SN meant dark green led. I didn't get a blink code in either case. It would flash a few times green before staying lit or dark

can you expand on last sentence

"It would flash a few times green before staying lit or dark"

I can understand locked/no error for shorted boards but he has exact same result with sn & ss isolated. He says it blinks fast then extinguishes.

That's where this has me baffled

[tom66]

Re: panasonic TX-P50C3B, wont turn on

Mine was lit with no short (SN removed) after about 6-7 flashes, and dark with a shorted Vsus after about 2-3 flashes.