Sony Bravia KD-65X85J No Sign Of life (No BL, Picture, Front LED,..)

[jason123]

Hi Folks,
I have a 65" newer (2021 model) that has no sign of life. No backlight, no front LED (assuming it has one) and no audio or turn on chime.

Photos below of the system

The CN6401 Connector has the following vitals:
STBY_3.3V is 3.432 V
BL_ON low (0.153 V)
BL_ERR low (0.051V)
POWER_ON 3.42 V (as soon as I plug it into the wall this comes on)
REG12V pins 12.7 V
TCON_VCC12V pins low (0.11V)
TCON_ON low (0.155)


Large caps are at 392V as soon as I plug into power

Seems like a Mainboard issue as it's stuck in no execution mode? But I need your expertise pls.

Things I've tried
1. Powered up with power to TCON disconnected. No power on cable (so TCON maybe not shorted?)
2. Disconnected Panel with all cables connected. Still no TCON_ON signal
3. Disconnected LVDS cables from Main to TCON. Still no power to TCON (probably expected)

Anything else to try or any thoughts?
Thank you

[EazyBone]

When the EMMC goes bad, all kinds of weird crap happens. No stb light, no backlight, no this no that. It's pretty common fault on these sonys that I found the main board is the issue. Power supply looks good with voltages. Sony is apparently plagued with bad EMMC.. this is likely your issue.

Unless you have the equipment to change the EMMC and have the software which is not likely.. just replace the main board.

You can try and test the panel/TCON if you want.. but these symptoms don't happen with a dead panel that I've seen.

[jason123]

Thank you, one on order. I have a way to replace the part, and the part is available on ebay, it looks like. I don't have the code or the programming software unfortunately. Thanks again, will post an update once I get the Main board. FYI.. I was board and tried to reflow the ARM processor, just in case, and that made absolutely no change.. sounds like eMMC issue like you said.

[EazyBone]

Yea I can't find a place where the software is online either. You just have to take it off a good board. Even if you copy the software for whatever reason it can (not sure on all tvs) corrupt Netflix/Hulu/prime any variation of those will no longer work again for some reason. It's unfortunate too as the EMMC is like 5 bucks

[Davi.p]

Try an emmc reballing and also ram chips..

PS: i think you'll not do, i think nobody listen to me when i say it..

[jason123]

I reflowed the emmc as well. Have you tried reballing? It doesn't get hot typically like a processor that's why i am not sure is something to pursue unless you tried it?

[EazyBone]

The EMMC gets corrupted,the software. the solder balls don't crack. It's not going to help. These aren't Vizio CPUs. Reflow EMMC not going to do anything.

[Davi.p]

Reflowing is not technically good, balls gets bad with time (this is my theory, i don't want to unroll all it here..), i have no tools to make reball, and never own a Sony with this issue, i think reballing of small chips takes not a week, maybe skilled person takes 2 hours, i always suggest this, nobody ever tried, i don't know what to say, i think stay sit hoping someone with the software is hard.. PS: (CPU also is BGA... remember though)
PPS: obviously there's a chance that bad balls with time generated errors in data writing phase and files / partition gets corrupted, but without SW in hand one can try..

[EazyBone]

Just watch Nick's TV videos. You'll learn this is not likely the case

[Davi.p]

So i have to watch tons of videos? I have watched only one and it's a waste of time, he replaced the emmc with no explanations.. if you have a direct link ok, otherwise i let stay..

[EazyBone]

Reading theories based on not having actual data to support it and then suggesting it to people seems like a waste of time. Unless you have supportive real data and experience.. then as you say in your response to me. Maybe you should not give your opinion on things you don't know about also... Waste of people's time.

[Davi.p]

Don't talk to me any more, you don't worth an answer, you are the perfect company of the ****..

[Admin]

Don't talk to me any more, you don't worth an answer, you are the perfect company of the *** one..

Posts like this are unfriendly and against the forum rules. The second time within a week. If you don't want to interact with a member you add them to your ignore list.

[Davi.p]

Honestly.. how might i take one post saying that my advices are waste of time? Nobody here has the crystal ball everytime, i suggest i thing, everyone can keep it or not on its technical basis, if a forum permited only 100% right solutions it had to be probably a paid service, i don't really know why i'm here explaining this, these are the basis of every free forum, it's mad to have to precise such a thing.. i'm attacked from both users, i respond, how bad can be this? Do you want me out of this board? I can do it, i left the Italian forum since march, for nearly same reason.. The right action, for my little opinion, that a moderator can take, is to ask Easybone: have you the proof my advice is bad? Ok you can call it waste of time, otherwise please shut the mouth and learn something.. maybe..
cheers..
.

[EazyBone]

I have learned that your advice isn't great yes. Appreciate you being here but make your own decisions. Stay or not.

[jason123]

Davi.p thanks for the advice. No attack here, just the cost of a new mainboard is far cheaper than reballing the emmc.

EazyBone a new board did the trick and TV is up and running. Thank you!

Davi.p the old board is available.. happy to send it to you if you wish to reball the board. Just pay shipping and it's free to you or anyone who wants it

[nomoresonys]

The exact problem wasn't nailed down, the main issue was no bl-on signal being sent from the mainboard and that is a mainboard fault. Just a fact.

[jason123]

BL_ON and TCON_ON are not coming from main board, and power_on is high- zero response from the main board. The main board is non-functional. I would love to get to the bottom of exactly what is wrong with the main board. I reflowed processor and eMMc. The proseccor is not warming up at all. No code being executed. Probably replacing the processor? What do you suggest I should try?

[nomoresonys]

I haven't done much of it lately but I think you can narrow down a little by testing the mlc caps near the eMMC and the processor, maybe see if you have 3.3 and 1.8 or so on the ones near the eMMC (IF those are present then you prolly have bad eMMC, YES bad) and maybe see if you have any near the processor that are very low ohms, test the caps for shorts while at it. The ones around the processor can be easy to misdiagnose if you don't know what exactly to expect, which is prolly hard without schemo. but the ones around the eMMC should be 1.8 and 3.3 (The eMMC can be tested with other tools, I'll let the ones who do that a lot explain) if others know factually about other ways then jump on in.

[Davi.p]

Thank you for the proposal, if had the time to invest i would accept it but i have tons of projects "with the 4 arrows".. i think shipment would be quite expensive perhaps..
do you mean new board is cheaper than giving it to a reballing center? obviously.. but my suggestion was if you were able to do by yourself, i will stay with my doubt, as always, goodbye.. cheers..