TCL 55P607 / 55P605 tcon dump

[ziddey]

Picked up this tv in non-working condition. On plug, the backlight would come on, and the led would flash about 16 times before cycling. So my initial guess was a fault with the mainboard. However, after holding down the reset button and plugging in power, it actually booted and stayed on. Still no display, but backlights good, and could hear roku sounds when pressing physical/remote buttons. No more cycling.

Next, detached one panel ribbon at a time, and got the respective white half, and banding on the other. Tcon seemed like common / likely culprit and are available cheap. Confirmed it revived the tv.

Saw replacement flash chips being sold as well, so I did some testing. Dumped the bad flash repeatedly and got consistent results. Dumped the good flash, flashed it on the bad one, and verified a bunch of times. Chip seems to be fine?

Retested the bad tcon and it's back to working. Closed the tv back up with the now working original tcon board, and will save the replacement for a rainy day.

So I'm curious what happened here? It seems like something was corrupt both on the mainboard (that was fixed with a reset) and tcon. Perhaps I'll be looking at a replacement mainboard in the near future?

Anyway, the problem tcon board is ST5461D04-1-C-7. Looks like it's used on a few different models as well. Flash chip is at IC6: GigaDevice 25Q41BT 4Mbit SOP8. AsProgrammer detected it as GD25Q40

Attaching the dump from the working tcon. Hope it helps someone in the future.

md5sum: d840252fccd1ea1a70bf36148d34c68d

[CapLeaker]

Re: TCL 55P607 / 55P605 tcon dump

Maybe buggy firmware, or a gone bad firmware update?

[handsworth]

Thanks. I picked this one up today off the curb. Plugged it up and immediately thought Tcon. Had same symptoms as yours. ( blank screen ). Had good tcon leftover from 55S405. Tv works.

[gpatadia]

hi ziddey
can you upload that dump

[ziddey]

not sure what happened to the attachment. here it is again

[gpatadia]

thanks

[howardc64]

Keep getting "Invalid File Specified" when trying to download the ST5461D04-1-C-7 T-Con flash rom file. Anyone else having access difficulty? Pics on post #1 don't post either.

[Diah]

Keep getting "Invalid File Specified" when trying to download the ST5461D04-1-C-7 T-Con flash rom file. Anyone else having access difficulty? Pics on post #1 don't post either.

how about this

[lotas]

Keep getting "Invalid File Specified" when trying to download the ST5461D04-1-C-7 T-Con flash rom file. Anyone else having access difficulty? Pics on post #1 don't post either.

I downloaded from the first post and from the fifth one too, everything is fine, but some photos are now opening with errors....

[howardc64]

Thanks Diah Yours and post #1/#5 downloads fine now as well as pics showing properly in #1. I guess server glitch.

My rom file differs (a bunch of random bytes) from these. TV (TCL 55S405) at a travel location so will install the flashed tcon in 2-3 months and report back.

[howardc64]

Acquired another TCL 55S405 with backlight but no screen. Failure is exactly same with TCON flash corruption. Looks like TCON ST5461D04-1-C-7 is prone to this failure. Here are some stats + failed ROM dumps and comparisons.

- 2x TCL 55S405 with TCON board ST5461D04-1-C-7 with backlight on and display blank
- Both TCON flashed with good.bin from post #1 and TV works.
- Diffing good.bin with both failed flash TCON image shows mostly single bit errors often in the same bit within the byte.
- Diffing both failed TCON flash image shows they are EXACTLY the same except a single bit.

So why is this failure so common? (ebay seller seems to sell many of these flash chip preflashed with good image, presumably same as good.bin)

- system update caused corruption?
- flash chip random corruption? These are NOR flash technology which is for high durabiity and reliability

Will use these TVs with good.bin flashed TCON and see if stays working. Also will electrical tape the buffer board guard as preventive for future flex+COF failures.

Both failed TCON flash image attached for anyone curious

[lotas]

The problem is precisely in this flash (GigaDevice 25Q41BT), it is installed in some monitors and there was a problem in the firmware, after replacing it with 25Q40 there were no problems.

[howardc64]

The problem is precisely in this flash (GigaDevice 25Q41BT), it is installed in some monitors and there was a problem in the firmware, after replacing it with 25Q40 there were no problems.

Great info. Thanks. Will order 25Q40. Does Giga Devices or Winbond brand matter?

[lotas]

Here you need to experiment, there are motherboards where there was a flash GD and after replacing it with W it did not start.

[howardc64]

Here you need to experiment, there are motherboards where there was a flash GD and after replacing it with W it did not start.

Thank you. I'll replace with same brand. I think I only see GD on these TCONs so far.

[howardc64]

lotas There are many GD25Q40* available, most differences are previous (GD25Q40C) vs newer versions (GD25Q40E, digikey in US require min 9000 tape reel purchase) and max temperature rating (85C vs 105C vs 125C) Most easy to get is GD24Q40C 85C part. Does this matter?

[lotas]

I don’t know, put a regular one, why put a high-temperature flash in T-CON.

[howardc64]

I don’t know, put a regular one, why put a high-temperature flash in T-CON.

Thanks. Just checking. 85C part seems good enough as you suggest

[ziddey]

For what it's worth, I've been using the tv with the original reflashed tcon board just about daily since I made this point, so almost 3 years now. TV has taken multiple roku updates without issue, although I imagine there probably haven't been any tcon updates, if that even was to blame originally. 25Q41BT

[howardc64]

For what it's worth, I've been using the tv with the original reflashed tcon board just about daily since I made this point, so almost 3 years now. TV has taken multiple roku updates without issue, although I imagine there probably haven't been any tcon updates, if that even was to blame originally. 25Q41BT

Reassuring Do you still have the failed tcon flash image? Would be interesting to compare it with the 2 failed ones I posted to see how similar.