Panasonic Plasma TH-P42V20A - 1 blink

[tw2005]

Well, I picked up yet another Panasonic, the baby to my 50" V20, the 42".

Advertised as "As advised by TV technician over the phone based on error code of flashing lights when switching the TV on, we believe the power board is faulty."

Based on that the lady was considering jumping in and getting a P-board from the UK.

But for those who've been around these a bit, when thinking P-board, think 4 blinks, SOS 4, think shorted SC board.

Now I never even quizzed them about the code, I know what this is, for sure. I'll just rip the back off, have a quick probe of the SC, chuck one from my stash and she's done and dusted

Nup.

No short on SC2, Q661 good.

So, isolateed down to just the A & P boards, expecting a 10 blink maybe since the "Tech" is quoting P-board.

1-Blink

I hate 1-blink, our boards are unique to us, impossible to find.

Going back to my P42X20A 1-blinker which I posted up a couple of years ago, accidentally discovering was the PD4 panel data Flash SPI corrupted.

So, how's my luck?

Found I had a 42" FHD budget A-board (U20 series)which was dead with IC9304 present.

With my $10 chinese programmer, I copied the existing data to a folder just in case I was wrong, blanked IC9304, copied the dead boards data to another folder, then wrote that to my 1 blinker.

and now the TV is working , image is good but i know it's not the same file but i can't see any issues with the display, I'd be happy with it.

just thought this would be good for future reference.

this TV has done a mere 3800Hrs in 5 - 6 years.

[TVRepairNoobie]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Way to go!!, thanks for the info.

[tw2005]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Still chipping away at this one.

I'm thinking in some instances the PD4 Panel Address data is the same over the differing sizes. Now in the past I've said it would be different but hat is an assumption based on differing part numbers but then I found this.

TH-P50V20A ic9304 TVRR330
TH-P50V20Z ic9304 TVRR330
TC-P50V20B ic9304 TVRR330

TX-P42G20E
TX-P42G20ES
TX-PF42G20S
TX-PR42G20 shows ic9304 TVRR330

I have no 46" aussie or european manuals which would have been nice to substantiate the theory as a manual can easily have incorrect data too.

So I jumped into the US market stuff.

Found TVRR248AAS used in

TCP42G25
TCP46G25

The last 3 letters is like a revision so I then find TVRR248ADS in the same 2 models

but TVRR248S used in

Panasonic TCP42G25 42" PLASMA TV
Panasonic TCP46G25 46" PLASMA TV
Panasonic TCP50G20 50" PLASMA TV
Panasonic TCP50G25 50" PLASMA TV

So I have the dumps of

(ic9304) TVRR330 from a 50"
(ic9304) TVRR??? from 42V20A , SOS1
(ic9304) TVRR??? from 42U20Z, currently loaded into the bad board and working fine.

I found a program Frhed ( free hex Editor) do a file properties and get this back

File name and path: C:\Users\TOSHIBA A300\Desktop\p50v20a\pd4 ic9304 .bin
File size: 2097152 bytes = 2048 kilobytes.

Number of hexdump lines: 80660.


File name and path: C:\Users\TOSHIBA A300\Desktop\p42v20a\pd4 ic9304.bin
File size: 2097152 bytes = 2048 kilobytes.

Number of hexdump lines: 80660.

Nothing learnt there. So then do a compare from current offset using the corrupted 42" to the good 50" and get this as reported different, all else is a match.

1) 0x149cb4=1350836 to 0x149cb4=1350836 (1 bytes)

So for curosity, do same for the data I've loaded from the New Zealand U20 series, results substantially different but remember this data is working in the TV.

76293 differing results!

SO back to the corrupted ic9304. Find the offset referred to and find as seen in the image, 01 in the good one and 05 in the corrupted data.

So I've programmed the original contents and reinstalled the board, to confirm bad and SOS1.

Then I editted the 42" contents replacing the 05 with 01, reprogram , install the board and now it's working.

I'm happy enough to assume that with only a single byte different they were originally the same files in both the 42 and 50, and that this TV is back to how it was.

[tw2005]

Re: Panasonic Plasma TH-P42V20A - 1 blink

something else I noticed. After re-creating the 1 blink, when I installed the board it did not turn on, but what it did do is go through the start-up then quit as in normal standby.

then I just used the remote to turn it on and normal operation. It was as if it did an audit of that chip , confirmed good and reset to standby.

[tw2005]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Just some images of this working, boring i know.

[vinceroger69]

Re: Panasonic Plasma TH-P42V20A - 1 blink

It looks a great picture and seemed a easy fix, i wish i could find another cheap/free panasonic plasma to repair, my panasonic TH42P285B is still going great after replacing the usuall two capacitors to fix the 10 blink code it still has a great picture too. Do you tend to repair any other make plasma or you just concertrating on panasonics.

[tw2005]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Panaholic I'm afraid, if you catch me fixing anything else, i was either desparate or it was a good deal.
Old dog can learn a new trick, just can't remember them all so I focus on ones I'm familiar with.

Just find that I like the schematic and component level details in their manuals and I'm yet to see a panel with an image issue from age in Panny.

[vinceroger69]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Sometimes its good too concertrate in one make you get to know most of the faults and the usuall repair parts, but if your like me once you repair a decent set you find it hard to sell it on etc as they have great pictures etc.

[tw2005]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Sometimes its good too concertrate in one make you get to know most of the faults and the usuall repair parts, but if your like me once you repair a decent set you find it hard to sell it on etc as they have great pictures etc.

Hmmm, yes. Mrs not talking to me right now. have 12 in the house, something about stop spending and start selling

[vinceroger69]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Yes i used too get that comment too i have sold a few lcds i have repaired and saving the money for decent tools ie hot air station etc.

[tw2005]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Yes i used too get that comment too i have sold a few lcds i have repaired and saving the money for decent tools ie hot air station etc.

LOL, just got my first station this week and that's my thinking.

It's a cheapie, TENMA 2062633 FARNELL (element14). Undoubtedly it'll be a rebadge. On the front cover rework is spelt REWOEK, note "E" is in fact next to "R" on a qwerty board.

Still learning how to handle and regulate it. No plans to do any serious work but I'm tempted to get a few buffer ICs and try restoring a couple of TNPA5336 & 5337 boards since they're almost extinct and very pricey.

Did not realise the air flow could be dropped, very frustrating heating a chip and flux to 300c and blowing the chip off the board

[vinceroger69]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Thats a good price on that station im just after the hot air side though as i have a solder station already i will have too look what cpc has too offer as ebay is a bit of hit or miss regarding there hot air stations.

[bikerbuddy]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Tw2005 Did you remove the eeprom chip from the board to read and write or on board .

[tw2005]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Tw2005 Did you remove the eeprom chip from the board to read and write or on board .

nope, and that's the beauty of one of these or similar. After that 1 blinker i had before and the couple of A-board conversions I've done, I thought would'nt it be great for the newer A-boards to play with and be able to read/write to the chip on the board..


I will say the test clip I got is absolutely shit. stopped working the first day, the cabling started to break internally and the clip is just a cheap knock off with no quality in the pins as they lost tension. I've managed to resolder the leads and dodge the pins up enough to get by but for how long, not very I'd say.

I've used it on a bios chip to view and edit the serial number l& mofel number loaded into that to match it up on one of my laptops just for fun and that worked too.

I guess if people had these and the time and effort to grab the dumps off all the eeproms from various models, store them into a library , could be handy .

But from what i see $7-8 for some of these chips programmed which is cheap. I think it cost me probably $30-40 from Panasonic.

I think I need to make my own set up using either a 3M clip or a pomona but I'm worried about getting a fake if I go for the cheapest deal on fleabay.









They're all 8 pin except 1 48pin Flash chip and that one as far as I can work out is the software for the GUI I guess if I've termed that correctly(menus etc) There are other chips that are used in different sizes like the tuner data.
(The older boards like 50G10, S1, the panel data is on a 48pin device)

As I've said if you're stuck finding an exact A-board revision, but the board is physically and electrically the same, the only difference will be the data stored on some of these chips, some chips with have the same.

So you get that 50" board for your 42", grab one of these, save and label the dumps from both boards, rewrite the 42" data to it and hey presto the board has a personality change into the old board complete with it's settings, running hours and fault code history.

If you're really lucky, they're all topside on the board and you could do it insitu, but I think they're underneath.

And if your original board was a 1 blinker and suddenly the replacement went 1 blink, bingo, you know it's corrupted data on the old board.

Desoldering and transferring physically is how I've done it but it's a lot of work and easy to accidentally dislodge or lose tiny parts nearby like resistors and caps which I almost did , just lucky i found out which I spotted it stuck to the iron tip.

[Telefixer]

Re: Panasonic Plasma TH-P42V20A - 1 blink

Well that's all good reading!
I have a 50V10Z, one-blinker. But it will occasionally start up, so I;m thinking it's not corrupted data, as an EEPROM won't fix itself!
Any ideas?
Guys I've also got a 42ST30Z. I'll start another thread, it's gone from 7 blinks (Changed the normal IGBTs and their diodes and the little driver ICs) and now it's 6 blinks, 8 if I disconnect the SC control cable SN20. (SN board is SC plus SD and SU on one board)