Panasonic P42X20E 4 red blinks

[V3dran]

Re: Panasonic P42X20E 4 red blinks

Ok, I'll test tomorrow and post the results, maybe you are right abot the lock out system
(maybe 15V are sent to the SS board which is fault ,and then Vsub is not applied...)

Another question:
my SN board is TNPA5066 AB 2 SN
It pobble to use a TNPA5066 AC 2 SN?

Since I found that my SS TNPA5072 AC 1 SS can be replaced with a TNPA5072 AF 1 SS (n the way) because the only difference are the connectors for the ribbon cables,
maybe be the same with the SN board?

From the pictures seems that the only difference is the passive cooler

http://www.displayland.ru/images//zi...TNPA5066AB.JPG
http://2micom.ru/ocf/imgfiles/full_TNPA5066_AC.jpg

[tom66]

Re: Panasonic P42X20E 4 red blinks

I would imagine they're compatible, couldn't guarantee it but likely so. The bigger heatsink may be for a bigger screen size that needs more drive current to make a bright picture.

[V3dran]

Re: Panasonic P42X20E 4 red blinks

Ok, I'll wait for the SS first

I found here that they are compatible
http://tvpartsfast.ecrater.com/p/112...1lfuu-sn-board

At the end I can swap the heatsink since I cannot find the AB for a decent prize

Thank you again for the support

[V3dran]

Re: Panasonic P42X20E 4 red blinks

Update:

I left completely isolated the SN during the week (even the flat cables of the panel)
Changed the SS board, with SN disconnected (only flats attached) 6 blinks
Then I attacched the power on the SN without the S20 connector 2 blinks.
I reattacched everything 4 blinks.
Now I'm afraid that I have not fired the new SS since now without the SN gives 4 blinks (was 6 first time)...


I'm gonna search for a new SN board :S

[tom66]

Re: Panasonic P42X20E 4 red blinks

Some Panasonics will emit a fault signal if a board isn't plugged in. If the board didn't burn before, it's very unlikely it will burn again, unless there is a fault with the panel (which would write the TV off anyway...)

[V3dran]

Re: Panasonic P42X20E 4 red blinks

Most mofsets on the old SS board were burned so that's why I replaced it.

When I tried the old SS board with SN completly disconnected I got 4 blinks, Vsus on SS 0V, 15V goes up to 15 and then 0

4 Blinks SOS:
- regulation issues with any of the voltages output from the power supply
- wrong diagnostic by the A board

After I replaced the SS board with SN completly disconnected I got 6 blinks, when I checked Vsus on SS it was 60-70V and going down

"The TC-P42X2/C2 series have an energy recovery circuit in the SN boards. This circuit monitors the scan board output and the sustain board output. Any abnormality on this circuit will trigger the 6 blinks code. If SC20 is disconnected or is not seated properly, the TV shuts down with 6 blinks."

After that I connected the SN board (only power and SN3, no SC20 from which it obtains 15V), 2 blinks

2 Blinks SOS:
- Missing P15V
P15V is not been generated by the P board.
P15V is been affected by one of the boards it is connected to (A short circuit of the P15V)
- Wrong diagnostic by the A board

After that I put the SC20 flat, 4 blinks...

I then redisconnected totally the SN board, 4 blinks, Vsus on SS 0V, 15V goes up to 15 and then 0

[tw2005]

Re: Panasonic P42X20E 4 red blinks

Hi there. just reading this fault and I too have a 4 blink code on P50V20A full HD about 14 months old.

Interesting fault to say the least. I isolated the SC board and the blinks changed, green led lit on the SS and managed to measure VS at 204 volts under this condition for the 3 seconds the set powered up.

When the Sc is connected 4 blinks and no led lit on that board. So I've headed for the SC and so far there are banks of FETs and diodes dead short all over this board.

I'll check the buffers next after I desolder a heap of parts.

[V3dran]

Re: Panasonic P42X20E 4 red blinks

Hi,
you are lucky that you can isolate the SS board, in my case the SS depends on the SN and they removed the led indicator on it.
I visuallly inspected my SN board and it seems ok, only one 220uF/25V capacitor is dead
I'm not a electronic expert but is possible that only one capacitor make the entire board fault?

[tw2005]

Re: Panasonic P42X20E 4 red blinks

I never Isolated the SS board just removed the VSUS line to the SC and left the ribbon cable connected. Backprobed the VSUS connection and then powered up psu. It started, normal voltages present but then detected that the SC was not online so shutdown and spat out the 6 blinks for a bad SC.
When the SC was connected it aborted due to the dead shorts, no voltage and 4 blinks.

A bad cap could yes but I have not struck a Panasonic Plasma yet with one. Had one set with 10 000 hours on it and all the caps looked visually good.

Can't make out much in the photo except clumps of dust?

I'm confused about the SN board is that the same as the SC?

[V3dran]

Re: Panasonic P42X20E 4 red blinks

Yep it's the same, they integrated SU SD and SC into one board, SN