Black screen on Sony 65x90ch (65x900h from Costco)

[Adam Russ]

I have a 850e Sony that has a board for a 850f. The TV turns on still and once it gets to YouTube to play or something it crashes. The original owner said he replaced the board and it worked for a while and the same thing happened again. I also had this exact thing with a different TV, and I ordered the correct board to fix it. So you might have a wrong board in there.

BUT like we learn here, I also have a 65 Samsung that when I lookup the board it's listed as a 55 inch tv and ONLY for the 55 also.

Hopefully the version you need is cheaper.

They arent too bad. about 60 bucks on average. Hoping that'll resolve the issues. I'm halfway through checking these backlights on the 4 blink tv but so far the top half all checknout as working. can tell they made the zones smaller on this one (2 leds per zone instead of 3 on the H model). Im.hoping this one is easier to diagnose but I might need to double check it's boards are correct too. Thanks for the help before.

[EazyBone]

Don't forget that potentially it means the LED circuit. Bad power board can cause it also. So yes do the due diligence on testing the LEDs and the rest. I've never actually had a Sony with bad backlights yet.

[Adam Russ]

Don't forget that potentially it means the LED circuit. Bad power board can cause it also. So yes do the due diligence on testing the LEDs and the rest. I've never actually had a Sony with bad backlights yet.

Well I got it working again. Took it all apart. tested the led with a backlight tester, all were good with proper voltage and brightness. Put it all back together. Upon first turning it on, just a black screen. Unplugged left side lvds cable, still a black screen. switched to the right unplugged and got the display color test. Hooked both up and all black. Did a factory reset and it started right up. I'm wondering if somehow one of the backlights was loose or making a bad connection triggering the 4 blinks. I has previously swapped every board with a working one from a good tv and no change so I figured it had to be backlight related with the 4 blinks and no board fixing anything. But since backlight tested okay maybe there was a bad connection somewhere. Anyway, glad it's working and I can get this one out of here. Thanks again. I'll be ordering the correct. board on the other tv and hopefully they'll be out of my room finally.

[Adam Russ]

Just an update on that first tv that had the wrong main board. I got the new main board in and did the firmware update. Still a black screen. Not sure if it really worth investing much more time into it. Last thing would be buying a new t con even though when i swapped them in the past it didnt fix it. That could be due to the wrong board being installed though.

[Adam Russ]

Second update. Tried to see if a factory reset would change anything. I left it on for about 5 mins to do it's thing and it suddenly shut off. Now the power supply is dead. Have you guy seen a new main board cause a power supply to go bad before?

[Diah]

Well I got it working again. Took it all apart. tested the led with a backlight tester, all were good with proper voltage and brightness. Put it all back together. Upon first turning it on, just a black screen. Unplugged left side lvds cable, still a black screen. switched to the right unplugged and got the display color test. Hooked both up and all black. Did a factory reset and it started right up. I'm wondering if somehow one of the backlights was loose or making a bad connection triggering the 4 blinks. I has previously swapped every board with a working one from a good tv and no change so I figured it had to be backlight related with the 4 blinks and no board fixing anything. But since backlight tested okay maybe there was a bad connection somewhere. Anyway, glad it's working and I can get this one out of here. Thanks again. I'll be ordering the correct. board on the other tv and hopefully they'll be out of my room finally.

in which test you get switched to the right unplugged and got the display color test ?

[Adam Russ]

in which test you get switched to the right unplugged and got the display color test ?

That test was on the other tv. That tv is working again. My last message was the forst tv where I found out the tv had the wrong main board in it. However when i swapped out the board and then did a firmware update to pair it, it still didn't show anything but a black screen. Then I tried to factory reset it and it didn't the turn of and turn on typical procedure. A few minutes layer it just completely turned off. The power board which was working fine up to that and had proper voltages is now dead. I'm curious if anyone has had experience where a main board has caused the power supply to suddenly fail after installing it.

[Diah]

That test was on the other tv. That tv is working again. My last message was the forst tv where I found out the tv had the wrong main board in it. However when i swapped out the board and then did a firmware update to pair it, it still didn't show anything but a black screen. Then I tried to factory reset it and it didn't the turn of and turn on typical procedure. A few minutes layer it just completely turned off. The power board which was working fine up to that and had proper voltages is now dead. I'm curious if anyone has had experience where a main board has caused the power supply to suddenly fail after installing it.

show yours power boards socket and it print chart on it to know the pins name... also take it out and just plug it alone in wall socket measure any voltage you have on the socket which it before go to main boards.( this measurement should black probe on cold area chassis/GND and the red one on pins