Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

[thesteve]

Re: Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

Thanks, this is all great information!

So I have a matched pair of T-Con & main board from a supposedly known working set (cracked screen).

My two previous attempts at USB update seemed to work but ended in failure.

Do you guys think this was because the model number (and panel size) of those previous boards was a mismatch?
Do you think I should try the USB firmware update again with this latest well-matched main board?
I think the info on the USB is good, because as I mentioned, the TV (and flashy USB stick) went along with a long sequence of read/write/thinking LED flashes consistent with everything working... it just didn't end well.

To be sure, I recopied over the file to the USB just in case I possibly corrupted something by removing it from my laptop without first "ejecting" it.

Maybe if the t-con board knows the panel, I should use the old t-con board (?)

What is meant by "end of lifetime." You mean Sony doesn't provide the firmware file? I found a file for the EX720 on a Sony website.

[Davi.p]

Re: Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

Do you guys think this was because the model number (and panel size) of those previous boards was a mismatch?
Do you think I should try the USB firmware update again with this latest well-matched main board?

Yes and yes.
What do you mean for old tcon, original one?
Is not the tcon that knows the panel but mainboard that knows tcon, if model strings doesnt match the tcon is disabled, if i remember there are two enable signals from/to tcon.
End of life mean that emmc contains a counter that considers that after tot acesses it is no more good and must stop working, for me its only a programmed obsolescence mechanism..

[thesteve]

Re: Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

Correct, I should have said original tcon.
So I think you're suggesting I use the new main board along with its matched tcon board and update the firmware.

What is "tot accesses?" Is that Total? Could this Sony strategy be explained to me a little further please? Are you saying Sony prevents an old dog from learning new tricks (being reprogrammed to work again like I'm trying to do).

Just to repeat past posts and so we're all on the same page, my TV still works 100% with its original tcon board and main board (briefly). Well, not 100%.
I mean that even after unsuccessfully trying to replace the bad HDMI chip on the original board, the Sony boot logo still comes up perfectly (using the original boards), but since the HDMI chip is missing the bypass capacitors and input resistors, it eventually shuts down.

[Davi.p]

Re: Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

Sorry, total accesses..
I cannot explain you much about end of life thing, never hit this argument much. So to resume it briefly, do an update, then go to service mode, update those few options, then hope for the best.. i warn you, it is possible that those bad situations are generated by a programmed obsolescence fact, to make a proof of this if you update your original board and follow the right manual steps maybe you brick also this board.. if this happens i have i test for you..

[thesteve]

Re: Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

Thanks, that's an ingenious idea.

I wonder if I should try to replace the missing tiny surface mount components first, though. If I apply myself it should be possible... it's just so incredibly stressful to deal with those microscopic parts.

It seems I have a Sophie's choice of sorts.

[Davi.p]

Re: Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

Yes stressful, if your attempts are made with an hot air that risks to make the pieces fly away... but if you would warm the board from the bottom, it is way more easy, it's only a matter of still hand and good plier... i mean using a simple tablet of alluminum on top of a kitchen stove..

[thesteve]

Re: Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

Well I have 30 days to return the latest eBay boards so it's worth a shot.

That's good advice. I think there's a chance the replacement HDMI chip is properly soldered in place. So I was thinking of just using less than a drop of some kind of glue to stick the surface mount resistors/caps in place, and then once they are fixed I could solder them with a fine tip iron.

They're so small, there's no identifying marks on them... they're either black or tan in color. I hope they are all the same. I guess I can confirm on the schematic but now you see another reason I did not want to attempt this.

I have renewed courage, though. Thanks.

[Davi.p]

Re: Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

Ah good, i had totally forgot the glue technique, never tried, maybe it needs an heat resistant one..(?)

[thesteve]

Re: Sony experts? 2nd bricked BAT Board after firmware update KDL-55EX720

Good point. I do have hi-temp epoxy I can mix up if necessary.

[thesteve]

Got it!!!

So after two days of no reply from the eBay seller, I figured I would risk trying the USB firmware update and if it didn't work I'd just return it since the seller was ignoring me.

Well one thing I only mentioned in an earlier post was that I had to trim the ears on the LVDS cable for it to fit in the first and second eBay main boards I tried. This was because the connector was slightly different. (I should have taken this as a hint that I had the wrong board.)
So with the ears missing, when I would plug it into the proper board (my original board or the correct 55" EX720 board I just bought) there was room on either side for the cable to be off-center. I knew this because I would get error LEDs if it was not aligned perfectly.

So I before trying the USB update, I had to verify that the cable was centered. It took a few attempts. Well on the third try, I turned it on and to my absolute shock I not only had the sound of snow, but I had real snow! A beautiful picture!

So I can't take any credit for doing anything at all with this repair other than my mistakes. Too bad I'll never know if the USB update was the problem or not.

Oh well, at least I can verify that if you replace the main board with one from the same model and replace the matching T-Con board as well, it will work.

Thanks for everyone's replies. They kept me trying, and now I have my beautiful 55" Sony working once again as a second TV just in time for football season!