Panasonic TC-P50U2 Main Board Suffix Codes

[Dadioh]

For background I am an electrical engineer with a full time design job and a hobby repairing MacBook logic boards. I know my way around schematics and have a decent microscope and soldering setup.

I had a lightning strike near my home which has knocked out the 3 HDMI ports on my 2.5 year old Panasonic TC-P50U2 set. My Mac Mini that was connected to the TV through HDMI is fine. This is actually the second time this has happened but the first time was during warranty period and they changed the main board. The first time it also took out the HDMI ports on my Harmon Kardon receiver so I just stopped using the receiver for switching HDMI signals. I don't know why the HDMI ports are so sensitive. All of the pther ports and functions are fine. I had a look at the schematics in the service manual and I see a couple of TVS diodes on the I2C data and clock but those are really for ESD not lightning. Maybe the grounding on the HDMI ports is not references solidly to the TV chassis ground...

I measured the 3 HDMI ports and the only odd thing I could see waas that the impedance to ground on the I2C signals was OK on ports 2 and 3. I think 4.7K and 47K going from memory. But HDMI port 1 was something like 40 ohms to ground. Unfortunately these signals go straight to the signal processor chip which is a BGA that I am not about to change. Likely the DSP chip itself is fried. Not exactly sure why the fault on HDMI port 1 also affects ports 2 and 3 given they seem to have different I2C busses.

Anyway, that is the background. Now I am on the hunt to replace the main board TNPH0831 with suffix code AJ. Can't find them anywhere in stock. A couple of old eBay listings but nothing current. I have found a few of these with different suffix codes from different model TV's that appear to have the exact same components and IO connections.

So here is the question. The suffix code seems to be controlled by the bank of 5 resistors. If I got a board with a different suffix code could I "change" it into my suffix code by adjusting the resistor network to match? Or is there firmware on the board that would also need to match up to the suffix code.

Any help appreciated.

[tom66]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

The suffix resistors are just a note for production, they are not tested by the board, so changing them won't make any difference. What you can do is check the model # and see if the D board type is the same, and all connectors fit. If so, it will probably work.

[Dadioh]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

The suffix resistors are just a note for production, they are not tested by the board, so changing them won't make any difference. What you can do is check the model # and see if the D board type is the same, and all connectors fit. If so, it will probably work.

Thanks for that. Using resistors as visual markers... tricky ;-)

I will look at the D board markings and see if that is the same between the 2 models I am comparing.

[kevn96]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

I am having the same issue, however am a little less informed. I have the same board number with suffix 3A. I have found boards that came out of a TC-p50S2, but my TV is a TC-p50U2. Did you find a board that works on your U2?? I have found boards with the same suffix, but don't know if they are the same model number... How do I make sure that they are compatible? Thanks

[tom66]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

Just match the suffix - model number isn't important except maybe in the service menus which have the model number written down, but TV still works fine.

[kevn96]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

The suffix is determined by the resistor location on the board correct? or is the 3A the suffix? or do both have to match? Thanks

[tom66]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

It's determined by the resistor matrix, if present; if there is no matrix it will be printed on the board somewhere.
http://www.youtube.com/watch?v=IrfefQ7SIXk

[freakaftr8]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

I replace the HDMI codec chips in those boards before their pain in the * but it is possible for you if you can't find the boards look up the chip. Its the ic that goes to the hdmi. Follow the traces.

[kevn96]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

got it.. Thanks! now I just have to find a "AJ" suffix board... Everyone is out of stock!

[kevn96]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

I replace the HDMI codec chips in those boards before their pain in the * but it is possible for you if you can't find the boards look up the chip. Its the ic that goes to the hdmi. Follow the traces.

the issue with mine is not the HDMI. The set won't power on. I followed the troubleshooting here
(slide 32),flow chart NO, NO, YES, replace the A board. I did have a shutdown with 10 blink code for a little while, but then nothing..
Unless you know of what else to check on it.?

[freakaftr8]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

Well here's the ghetto way of going about it and have run into Panasonic'sthrowing false error codes for some reason . you could temporarily disable the SoS 10 output to thepower supply only if all the other checks come up good no failed boards as sustain boards are fineand power supply has no shorts. I'm actually running a 42 inch panasonic tc-p42s1 that way right now and it turns out that there is some low esr capson the main board that regulate voltage on the 3.3 rail. And what I get is some static on the screen upon startup but it dissipates immediately. So it's really not a big deal to me and it would be cheaper if I were to find in a board instead but until that happens I'm just going to keep running it this way. Its been like this for a year and a half no problems

[freakaftr8]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

it's actually kinda tricky and I wouldn't recommend it but I have done it when all else fails. of course running it this wayis not generally a good idea because if a component actually shorted requiring the 10 blink SOS shut down it wouldn't shut down and it will be probably blowing a part up

[Dadioh]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

I replace the HDMI codec chips in those boards before their pain in the * but it is possible for you if you can't find the boards look up the chip. Its the ic that goes to the hdmi. Follow the traces.

I traced the HDMI signals and they go to the large component with the heatsink glued on it. I assumed that this was a BGA part so not much chance of me replacing it. I have good soldering skills and can do QFN's and smaller logic devices but without a rework station not sure I would try a larger BGA package.

Do you know the part number and a source to buy the HDMI codec from?

[Dadioh]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

Just match the suffix - model number isn't important except maybe in the service menus which have the model number written down, but TV still works fine.

The issue for me is finding an AJ suffix board. All the online stores are out of stock and none of them answer my emails about when they expect more in stock. I called Sears parts and after a while on hold they tell me Panasonic does not make this part anymore so maybe that is why everyone is out of stock.

Seems crappy that a 2 year old TV no longer has parts being made for it. Talk about planned obsolescence :-(

I was really hoping I could use a different suffix board but I don't want to spend >$100 just to try an experiment to see if it works.

[freakaftr8]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

I traced the HDMI signals and they go to the large component with the heatsink glued on it. I assumed that this was a BGA part so not much chance of me replacing it. I have good soldering skills and can do QFN's and smaller logic devices but without a rework station not sure I would try a larger BGA package.

Do you know the part number and a source to buy the HDMI codec from?

Yea, without a rework station, removing that IC and replacing will not work out.

[electronicsurplus]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

it's actually kinda tricky and I wouldn't recommend it but I have done it when all else fails. of course running it this wayis not generally a good idea because if a component actually shorted requiring the 10 blink SOS shut down it wouldn't shut down and it will be probably blowing a part up

Question? How exactly are you disabling the SOS? By removing the cap or ?

[Dadioh]

Re: Panasonic TC-P50U2 Main Board Suffix Codes

Finally found an AJ board from tvpartsguy.com. Replaced it last night and all is well. Had to pay $160 plus shipping for it These boards are hard to find for some reason. I was told Panasonic stopped making them. My TV is only 3 years old and can't get parts. Doesn't seem right.