PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Hi TW did you in the end change the SS and SN board or was you repair on the SN all right, i ask as i have a TX-P42C2B with shorted SS 5072 (RJP30E)and SN 5066 shorted (DG501/RJP63F/plus)but am waiting parts from Japan, as you are looking at £5 a go for RJPxxx over here, and look like it will need 7 or 8,your help may be called on. Flocko

SN repair worked for me but it was just Q451 that was short, nothing else!

How much more is wrong with the SN?

There are a number of revison boards that will do the job for both the SN & SS as there is a Sanyo with the same panel.

Who are you using in Japan?

[flocko]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Hi TW did you in the end change the SS and SN board or was you repair on the SN all right, i ask as i have a TX-P42C2B with shorted SS 5072 (RJP30E)and SN 5066 shorted (DG501/RJP63F/plus)but am waiting parts from Japan, as you are looking at £5 a go for RJPxxx over here, and look like it will need 7 or 8,your help may be called on. Flocko

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Well done!
You know if you had a scope you'd probably see the SS waveform looking poor and that'd save you a ton of time and money on a project like this.

Cheers, thanks.

yeah I was doing some self analysis and a scope was one thing that crossed my mind. The other was I should have just sourced the right parts. TBH I expected this to be a quick 4 transistor replacement.

Good example though if you're stuck for an A board what can be achieved.

Also exposed 1 cause for a 1 blink.

[tom66]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Well done!
You know if you had a scope you'd probably see the SS waveform looking poor and that'd save you a ton of time and money on a project like this.

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Well, it's been a long time coming but this TV is fixed. Well, provisionally.

Quick summary,

Started with SOS4 - shorted SS TNPA5072AC, replaced the shorted transistors.

This then revealed SOS1 - bad A board - later discovered corrupted FLASH IC9304 (panel addr data)

Purchased new Zealand A board and did full eeprom swap, ordered new OEM IC9304
This gave me the original Australian version board required.

SN had shorted Q451 DG501, used a DG502 I had, that fixed that.

had corroded ribbons from the A board, replaced them.

Ended up with bad discharge and image issues.

had no real idea there.

replaced C buffers, no change

Disconnected the right C board and picture was improved, appeared panel was not powered enough similar to a failed SS.

So got another board (SS) - fixed!

So lesson here was using what I thought was a reasonable substitute IGBT, IRG7S313UPBF caused me grief (not proven yet ) RJP30E4 were the originals.

TV has 6000+ hrs and with all the abuse it's copped ripping things in and out happy to say perfect picture.

$$ too embarassed to say but given the surgery I did on the A board, amazed i pulled that one off.

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

yeah tried all the obvious stuff but the video does not really capture what the human eye sees.

If I had to draw a comparison it's a little like a bad T-con solarisation which I've experienced on an AUO panel in a SANYO except with the plasma you get all the sparkles.

I remember with that one solid test patterns looked ok but complex images were messed up and negative looking in places.

Considering the C2 board had a damaged buffer ic, it's conceivable that maybe there could be an issue with the buffer ICs at SN20. There's no doubt that all 3 ribbons from the A-board were in a bad way and shorting in parts.

I just have a feeling some data signals are missing or messed up?

Not sure how many miracles I have left in the toolbox, I'm pushing my luck with this one, just wish it was not costing me as much.

[tom66]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Tried playing with the brightness/contrast controls? Try turning it onto ECO mode?

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Some more video a bit longer and is a good example of the change in display. TV station off for the night with still slides One looks quite normal.

http://youtu.be/vDtzIDV1YxI

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Yes there's a big question mark over what I've done. Big kick in the guts having that eeprom corrupted, was not part of the plan. I expected the issue with the original board was going to be the BGA chip.

Just throws a cloud over the fault finding process as to what is good or bad.


I can't believe these boards run with both the main processor and that PD4 IC as hot as they do. the PD4 with no heatsink is too hot to touch.

I did have the meter hooked up to the Vsus and the ERC Mid for a while, hardly changes from what I quoted, 1 volt at most variation, quite steady really.

Anyway parts won't be here before I go so it'll rest for 2 months, out of action for now.

[tom66]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

One possible issue is 50" firmware is set up to allow higher display brightness and maybe SN/SS cannot supply that. Try monitoring VAD/VE/VSUS on scene changes.

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

tried something and snipped a tiny portion of video. http://youtu.be/rzF6lKd47y0

5mins to upload 23sec of video. !!

Had a look at the ccts for the 42 and 50. C boards are the same just stretched for the 50, but how do you go when both TVs are 1024 x 768 but the 50 has 2 extra buffer panel connections as far as addressing goes?

Still worried about that particular EEPROM data and how it may cause image issues or not.

Has anyone out there put a larger model mainboard in and how did it go?

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Set you video editor to output 2Mbit/s MP4 with 192kbit/s audio, if you do not have a video editor use one such as avidemux.

Downloaded that avidemux, can't figure out what to do to resize or settings.

[tom66]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Any tips on videos, just did MP4 and it's 1Gb! youtube looks like it'll take forever.

Never done this before. Not great, missed some of the screen not 100% accurate but good enough for an idea, is pitch black outside so the camera shows over exposed and the flickers are on camera not to the naked eye.

Set you video editor to output 2Mbit/s MP4 with 192kbit/s audio, if you do not have a video editor use one such as avidemux.

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

just re-confirmed IC9304 (TVRR577) ADDR/DATA , FLASH I/F to the PD4 PDP control IC.
from the original dead A-board SOS1 replicates SOS1 on the replacement board.

Ribbons are stuffed now, just lost pin 1 on A20 P5v & pin 55 P5v A32.

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

I'll have to try again with the video tomorrow(today, 4 am here way too tired)

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

MID is from 1/3rd to 2/3rd Vsus, if ERC is working OK.

So the 97V I posted previous which is about 50% of Vsus falls smack bang in the middle of 33 - 67% you suggest.

That was when Vsus was 192V, now 92V, Vsus 197V which is where I left it after tweaking Vs at the Psu.

Just adjusted Vs back 192v and still 92V at ERC MID.

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

MID is from 1/3rd to 2/3rd Vsus, if ERC is working OK.

Any tips on videos, just did MP4 and it's 1Gb! youtube looks like it'll take forever.

Never done this before. Not great, missed some of the screen not 100% accurate but good enough for an idea, is pitch black outside so the camera shows over exposed and the flickers are on camera not to the naked eye.

[tom66]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

MID is from 1/3rd to 2/3rd Vsus, if ERC is working OK.

[tw2005]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Regarding the maldischarge on the panel, check the MID voltage on your SN and SS. I'd be quite surprised if it is an A board issue, especially if it varies with display intensity.

I thought TH-P42X20A was 720p (HD) so why are you talking about 1080p (FHD)?

Have a closer read, I mention 1080i in regards to what the Digital stations transmit. It is a 720P TV yes and will indicate 1080i popup on the channels that use that format.

One of the 3 A-boards I have is from a 42FHD I suspect looking at the extra data lines on the 3 outputs to the SN(SC),C1,C2 boards.

What would you expect for MID? I have no data.

The reason I suspect it's not voltage at this point is I can watch a channel and at times it looks ok.

I may see if I can video it and upload, which will be a first for me

[tom66]

Re: PANASONIC plasma TH-P42X20A, SOS4,1,10,6,8

Regarding the maldischarge on the panel, check the MID voltage on your SN and SS. I'd be quite surprised if it is an A board issue, especially if it varies with display intensity.

I thought TH-P42X20A was 720p (HD) so why are you talking about 1080p (FHD)?