Sony XBR-75X800G - Android start up only and dark blue screen

[NolesFan]

Check the LVDS cable (contact pads), replace with a new one...

Can clean the flat cable contacts with isopropyl alc. some use pencil eraser, not too roughly, can go over the connectors where they hook up lightly with a toothbrush, remember its making sure things are clean and getting good connection, don't want to be too rough and break something but you do want to make sure things are clean and getting good contact, I've suspected poor connections all along on this one. Could also be a bad or intermittent cable as suggested previously.

So i tried all the cleaning tips and nothing. Found on Ebay a full set of wires. I changed out the LVDS and the one between the PS and MB. Thanks for all the help guys, I appreciate it. nomoresonys I have another set Ill be trying soon, so hope you continue to comment. You didnt let me give up so Im looking forward to hearing what you have to say on my next set.

[CapLeaker]

I did all that you asked of me nomoresonys and nothing changed.
CapLeaker unfortunately I dont own an oscilloscope only multimeters
lotas I found one that is all the wires for this set. I’ll definitely get it a hattry.

That definitely is limiting options.

[NolesFan]

I did all that you asked of me nomoresonys and nothing changed.
CapLeaker unfortunately I dont own an oscilloscope only multimeters
lotas I found one that is all the wires for this set. Ill get it an try.

[CapLeaker]

Hi CapLeaker, I had the main board tested by a repair shop and they stated it tested fine. Do you still think it could be the main board?

Without seeing signals on the oscilloscope, how do you make sure that something is coming out of the main board first place? Other than that you just take out the parts canon and see what sticks. Not a proper diag. You gotta start somewhere and be sure the part works.

[nomoresonys]

So if all that checks out can try some other stuff, one that works sometimes is hold power button on tv down while plugging in power cord keep holding til a display comes up, might take 3 or 4 minutes in some cases. Just be careful if display does come up, it might be the service menu so don't change anything, if display comes up let it come up fully then let go of button let it sit a minute, turn it off wait 5 minutes then restart as normal.

[nomoresonys]

Can clean the flat cable contacts with isopropyl alc. some use pencil eraser, not too roughly, can go over the connectors where they hook up lightly with a toothbrush, remember its making sure things are clean and getting good connection, don't want to be too rough and break something but you do want to make sure things are clean and getting good contact, I've suspected poor connections all along on this one. Could also be a bad or intermittent cable as suggested previously.

[nomoresonys]

Remember simple first, make sure your flat cable ends are clean and not damaged and connected straight and secure, if nothing else try plug and unplug the connector on mainboard and powerboard a couple times to try to make sure the pins are getting good contact, same with cable from mainboard to tcon or panel.

[lotas]

Check the LVDS cable (contact pads), replace with a new one...

[NolesFan]

So since the TV has been sitting, before I was going to sign off, I decided to just turn it on. It went from powered off, to backlight screen with sound, to a cycling white red green blue screen and starts all over again. Hopefully video shows so you can see what I mean.

https://streamable.com/x0xsuc

[NolesFan]

Ok, so with new tcon, try same test as post #126, remember vone IS vgh, see what it is with both ribbons connected, if it isn't optimal check again with one cable at a time connected.

nomoresonys, sorry I just saw the emails about what you want me to try again. I will test it the next chance I can and let you know the results.

[NolesFan]

what you need to do first is to check the LVDS with an oscilloscope and flick around the menus while watching each pair when it blue screens. If the LVDS pairs aren't changing while flicking around, the problem is the main board.

Hi CapLeaker, I had the main board tested by a repair shop and they stated it tested fine. Do you still think it could be the main board?

[nomoresonys]

Those little oscillos are getting so economical to buy, thinking that anyone wanting to try fixing their tv should prolly have one. I can make room on the bench for one of those small ones.

[CapLeaker]

Well that's our fault not yours. Been meaning to get some more gear just been too lazy lately.

Ha! Maybe I should come down and help you out in that situation... lol. Carry on, I'll shut up now already!

[nomoresonys]

you guys were doing pretty good here. Maybe sometimes it's not quite fair for me to chime in, because I have some gear to my disposal that most others don't have.

Well that's our fault not yours. Been meaning to get some more gear just been too lazy lately.

[CapLeaker]

Indeed CapLeaker you said it all, an oscilloscope would make it SO much easier.

you guys were doing pretty good here. Maybe sometimes it's not quite fair for me to chime in, because I have some gear to my disposal that most others don't have.

[nomoresonys]

Signal is signal, lotas... o.k. maybe a standard low end oscilloscope doesn't cut it, but the same principal remains. At the end of the day it always boils down to having the right equipment to do the job. Very good observation from your side and shows you paid attention!

Indeed CapLeaker you said it all, an oscilloscope would make it SO much easier.

[CapLeaker]

V-by-One HS is an electrical digital signaling standard that can run at faster speeds over inexpensive twisted-pair copper cables than Low-voltage differential signaling, or LVDS.
Here you need a cool oscilloscope to see something.

Signal is signal, lotas... o.k. maybe a standard low end oscilloscope doesn't cut it, but the same principal remains. At the end of the day it always boils down to having the right equipment to do the job. Very good observation from your side and shows you paid attention!

[lotas]

what you need to do first is to check the LVDS with an oscilloscope and flick around the menus while watching each pair when it blue screens. If the LVDS pairs aren't changing while flicking around, the problem is the main board.

V-by-One HS is an electrical digital signaling standard that can run at faster speeds over inexpensive twisted-pair copper cables than Low-voltage differential signaling, or LVDS.
Here you need a cool oscilloscope to see something.

[CapLeaker]

what you need to do first is to check the LVDS with an oscilloscope and flick around the menus while watching each pair when it blue screens. If the LVDS pairs aren't changing while flicking around, the problem is the main board.

[nomoresonys]

Ok, so with new tcon, try same test as post #126, remember vone IS vgh, see what it is with both ribbons connected, if it isn't optimal check again with one cable at a time connected.