Trying to Save - SONY BRAVIA KD-75X780F - No Picture BUT there’s sound

[admxxx]

lotas

admxxx
No joy....

Tried covering both sides and no change in the screen whatsoever.
I could hear the OCD music playing and the TV was responsive to remote.
Just no visual sign of life on the Display.

Did you got 32v on the Vone ? Are both U-link on the COF boards connected properly (under the metal frame of the TV)?

[KYBOSH]

Did you got 32v on the Vone ? Are both U-link on the COF boards connected properly (under the metal frame of the TV)?

I never got 32v at Vone.
in my p previous post i mentioned i never got hardly any voltage at all.

im very sure the U-link films are connected properly as well.

[KYBOSH]

This this has been sitting/standing on my worktable for months now. I am ordering a new T-Con from Aliexpress today ($35). I need to start eliminating some unknowns!

[KYBOSH]

Got my t-con in today.
IIRC you cant just pop new components on Sony TVs but rather you need to install them and re-install the firmware.
Anyone know if that's the case with the t-con?

[Davi.p]

Sony needs a special pairing modality, unfortunately i took a note only on my dead tablet..

[KYBOSH]

Sony needs a special pairing modality, unfortunately i took a note only on my dead tablet..

I found the KD-75X780F service manual (not sure why I assumed it would be hard to find) and at first glance it doesn't specifically speak of any pairing procedure but it does give instructions on doing the firmware update which I have done before.

It also has a flow chart on how to proceed when you have a NO PICTURE situation.

Apparently the FFC cable is the first thing under suspicion and the panel/T-con is the last.
I never considered the cable...

Not sure if I can rule out the Mainboard even though I get sound and input responses with the remote control...

[Davi.p]

i do not remember this entire thread, i don't even know what's the result of the new tcon board, if it is no display (it seems so) i can't help you, i remember i disucussed this pairing task in an old forum now closed, and no notes on my cellular/PC , only the dead note on tablet, i think i would be happier if i would find a very simple app to sincronize the very few files that i use commonly, years ago i wrote a terrible script to do this but i did not work so well.. what i recall is that in that discussion i did not found in time the answer to help a.guy, the requester user gave the tv to a sony center that made a secret procedure and fixed the tv, i tried to rebuild what they do and i thought i found the answer, but if i remember something i tell you.. what i remember maybe is that they have a special usb mem key with a script inside, i about sure of the usb key.. the script forces the main software to update the main.settings.to the replacement tcon/panel, Sony tv checks every boot some data on the tcon eprom, also a model ascii string, it must match the one stored in MB, maybe doing a deep reset the tv reinitializes, need to enter service menu blindly and perform the reset. check the service manual, some very old lcd had a shortcut to the service reset with key combination..

[KYBOSH]

i do not remember this entire thread, i don't even know what's the result of the new tcon board, if it is no display (it seems so) i can't help you, i remember i disucussed this pairing task in an old forum now closed, and no notes on my cellular/PC , only the dead note on tablet, i think i would be happier if i would find a very simple app to sincronize the very few files that i use commonly, years ago i wrote a terrible script to do this but i did not work so well.. what i recall is that in that discussion i did not found in time the answer to help a.guy, the requester user gave the tv to a sony center that made a secret procedure and fixed the tv, i tried to rebuild what they do and i thought i found the answer, but if i remember something i tell you.. what i remember maybe is that they have a special usb mem key with a script inside, i about sure of the usb key.. the script forces the main software to update the main.settings.to the replacement tcon/panel, Sony tv checks every boot some data on the tcon eprom, also a model ascii string, it must match the one stored in MB, maybe doing a deep reset the tv reinitializes, need to enter service menu blindly and perform the reset. check the service manual, some very old lcd had a shortcut to the service reset with key combination..

I have not tried the new TCon yet as it just came in the mail.
Apparently it requires a pairing procedure but that may be a simple firmware reinstall with a USB stick.
This does not require the display to be on bcos the update occurs (without user interaction) as soon as the USB with the firmware is detected.

In the video there is talk of potential FFC misalignment issues which i will have a look at.

New FFC cables are pretty cheap from encompass.com ($20 for the pair + S&H).
I may order them in order to follow the troubleshooting steps.

[admxxx]

In my case I replaced the t-con and it was a direct swap, there was no need for any pairing or firmware update.

[Davi.p]

i know an update works but you have an already updated sw, so what you do? there is maybe a method to force an unwanted update..

[Diah]

sony android TV, even if the last update installed on it,,, put it on USB stick formatted FAT32 MBR mode an USB V.2 on the side, not at the back, TV take it out from wall socket... if it had joystick presst and pull it down, keep in this position and plug it back in wall... release the joystick only after the front LED change from white to green..

the TV will write back the firmware from eMMC/NAND section first and related to USB to register all other HW boards back include T-CON.. PUNKT

[KYBOSH]

Thank you Davi.p admxxx Diah

I got my brand new LVDS cables in today and installed them first, as its the first step of the troubleshooting chart, but no joy. Tv behaved the same. I then installed the new TCon board. Also no change. I can hear music from the SONY setup screen l, the backlight is on but no picture image. Apparently Admxxx is correct that there is no firmware update needed for a TCon swap on this model TV but i may do one anyway incase the issue is firmware related somehow. It certainly wont hurt to try.

Before i do that i wanted to have a look at the buffer panel boards again to see if i could spot any shorted components i missed earlier. All of the capacitors read okay however (not shorted according to MM).

[nomoresonys]

Can you tell me the number of the update you are trying to install?

[KYBOSH]

Can you tell me the number of the update you are trying to install?

sony_dtv0FA60A0AA0AA_00004300_16072201000365.pkg

But for some reason it doesnt want to boot.
I went in and changed the name to update_loader as described in the video above.
But even then I got the pulsing with light but never got a green light no matter how long I held the (-) button.
The USB drive was blinking continuously indicating it was being read but nothing happened other than that.
Eventually the TV just restarted and went back to the normal solid white light.

[nomoresonys]

Can/have you tried a different one? I think it may work with the update_loader at the end of a different firmware. I think it can also take quite a while too in some cases to update. I would let it go a couple hours maybe. Plus as mentioned many times, these sonys are fussy, use no bigger than 8gb and trying different brands of thumb drives may be necessary.

[Davi.p]

Post a picture with a portion with original board sticker image, and the one on replacement board..

[Diah]

sony_dtv0FA60A0AA0AA_00004300_16072201000365.pkg

never got a green light no matter how long I held the (-) button..

keep the file name as it should dont rename it, press power on set and - , usb stick formatted fat32 mbr mode, keep press then plug tv in wall it will change from white to green

[nomoresonys]

Did you ever get green and white pulsing on indicator? If you did the tv needs an update nothing more. If you have somehow downloaded a corrupt firmware or something weird happened during download then it won't work. Try Diahs instruction if no joy, I would try in order and ignore if you have already tried some of them. 1, download firmware again and try both ways without the update_loader, then with it, no joy, try a different browser for download. No joy get a different number firmware and do same procedure.

[KYBOSH]

Diah nomoresonys
I reformatted the drive (with RUFUS) and installed the file again (changing the name to upgrade_loader).
I plugged the thumb drive into the TV and tried to boot from disk but it didnt take.
I unplugged it. This time I pressed both the POWER and (-) when I plugged it back in and as soon as I did i saw a solid green status light.
I let go of both buttons and the light turned from green to pulsing white. The thumbdrive was constantly active as indicated by the drives built-in LED.
When I returned about 40 minutes later the status light is a solid dim white and the TV looks normal. It seems the firmware update is complete but there is still no picture.

Davi.p
As you have requested.

Top = OLD (Original pulled from TV)
Bottom = NEW (Replacement ordered from Ali-E)

[nomoresonys]

Maybe ask Nick, he has done over 1000 sonys.