Panasonic 58-TXAX802B Stuck on Panasonic Logo

[Adrock]

I'm new to this place and repairing TVs so go gentle with me. I was donated this TV and after doing lots of research managed to determine my TVs A board needs changing.

The symptom I'm getting is that the TV powers up, I get a solid green LED and the Panasonic logo is on the screen. It stays that way for a couple of minutes before what seems to be a reboot, after waiting another couple of minutes it switches off. There are no red LED flashes at any time.

The remote control does nothing, I've tried getting onto the test pattern screen and that doesn't work.

I thought I'd just do a quick search for the part number (TNPH1100) and replace the board but there aren't any available, I missed out by a day on one of them.

I've read a similar thread on here and someone suggested dodgy NAND. My question is, would it be feasible for me to attempt a repair on the board or is it a lost cause?

I have experience with soldering and testing/returning old amps so I'm not completely green. Any help would be great.

[diif]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Have you tried a firmware update from USB ?

[Adrock]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

I have, I put it onto a FAT32 formatted USB drive and tried all three USB ports on the rear, restarting the TV each time.

I managed to find the service manual for a similar model, the AX800, and found its an eMMC chip, not NAND, if that makes a difference.

[Adrock]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

I opened the TV up and found a Hynix H26M31003GMR. I have checked the voltages and everything seems to be within the parameters mentioned within the service manual.

My question now is, do I have to use exactly the same product to replace what I'll be removing? Also, do I need to flash the chip before I install it on the PCB?

The chip installed is a 4gb, 3.3v, MMC4.5 eMMC in an 11.5x13x1.0 package.

I've found https://www.mouser.co.uk/ProductDeta...5T%252BA%3D%3D that on mouser. Would that work?

[diif]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

It needs programming first.

[Adrock]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

I rushed into this without thinking it through, it seems. I removed the existing eMMC this evening and now I'm stuck working out how to programme a newly purchased eMMC without spending lots of money on an eMMC153 socket I'll probably only use once.

Thanks for your help so far diif.

[diif]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

No harm done, it had to come off anyway.
It's usual to use a known working dump to program the eMMC as it's likely the old one failed due to bad blocks.
I've had a quick look but couldn't find a dump, but if you find one or want to chance copying what you already have from one to the other, you're welcome to post it to me and I'll do it for you.

[Adrock]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Thank you very much for the offer diif, I have found a firmware update online, which I downloaded originally. The zip file contained a .sec file, which I've never come across before. I take it that isn't what is required.

When I receive the new eMMC I'll be sure to contact you.

[diif]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Yes, t's a copy of the whole contents that's a required, often referred to as a dump.
The update file will just overwrite certain parts of the original.

[Paul112004]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Hi I have a tx-50ax802b version of same tv with same problem can I do exactly the same and are my part numbers the same as mentioned ect

I tried looking for service manual but cant find my model type would the 50 and 58 be exactly the same chip models ect

Could someone possibly direct me to where the nand is I bought the device to flash it but not sure where it will be

Thought I'd give it ago if it works good if not il just sell the parts instead

Thanks

[diif]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Hi I have a tx-50ax802b version of same tv with same problem can I do exactly the same and are my part numbers the same as mentioned ect

I tried looking for service manual but cant find my model type would the 50 and 58 be exactly the same chip models ect

Could someone possibly direct me to where the nand is I bought the device to flash it but not sure where it will be

Thought I'd give it ago if it works good if not il just sell the parts instead

Thanks

Under the big metal heatsink. A programmer capable will be over £100, you also need a good copy of the firmware (dump).

[Paul112004]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Under the big metal heatsink. A programmer capable will be over £100, you also need a good copy of the firmware (dump).

Hi I'm assuming your talking about the black plate that's screwed on top

[Paul112004]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Also thanks for replying I was meant to say before

The firmware latest file is that what I need to put in to the new chip

Has anyone managed to find out what software tv engineers use when they plug in the laptop into the service port on the board would be handy to know what it is called ive googled but find no answer to it

[diif]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Yes, I did a quick Google of the mainboard and it seems Ro be covered with a large heatsink but if you want to add photos I can confirm.

[Paul112004]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

I opened the TV up and found a Hynix H26M31003GMR. I have checked the voltages and everything seems to be within the parameters mentioned within the service manual.

My question now is, do I have to use exactly the same product to replace what I'll be removing? Also, do I need to flash the chip before I install it on the PCB?

The chip installed is a 4gb, 3.3v, MMC4.5 eMMC in an 11.5x13x1.0 package.

I've found https://www.mouser.co.uk/ProductDeta...5T%252BA%3D%3D that on mouser. Would that work?

Hi where did you manage to obtain the service manual please

[Paul112004]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Yes, I did a quick Google of the mainboard and it seems Ro be covered with a large heatsink but if you want to add photos I can confirm.

Ok thanks when I get home il send some photos to you much appreciated

[Paul112004]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

As requested photos of board I numbered so you can see and reply easier with the number of chip ect

I tried doing a usb firmware update but it doesnt even let you do that it just starts up stays on panasonic logo then turns of and gives u 13 flashes which I believe is loss of communication so could that be the big chip number 1
Or if not what part holds the firmware on the tv

Thanks

[diif]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

1, 2, and 3 look like processors. I see RAM connected to No1, are all four black rectangles identical as a couple of them are obscured.

[Paul112004]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Oh what an idiot I am I knew they were processors why did I think it was that part I needed lol

The bit I need is where the firmware is installed

I will take a closer picture for you of the area you mentioned and check them out and get back to you in a bit but I think they are the same yes but il check again

Thanks

[Paul112004]

Re: Panasonic 58-TXAX802B Stuck on Panasonic Logo

Hi yes all 4 look identical to me

I took few more photos if they are any good
Watched a video last night on a samsung tv the man removed a 8vlegged chip out in this machine then put a new dump into it refitted tov then worked fine
Should hopefully be the same on panasonic tvs
It had exactly the same issue stuck on logo

Il post the link if any help to others
https://youtu.be/TBQsCu0dzUk