Vizio M65-C1 no picture

[xfox]

Hello friends, today was playing with my TV (Vizio M65-C1), I had two spare t-con boards, so I tried to test if those are working and now I have grey screen, (no picture) tried to install tcon that was working, no luck, tried to replace main board, ribbons, same, VGH, VGL looks good, thinking ab firmware chip on LCD tabs, maybe someone have dump. Or any other ideas...
LCD - AU Optronics model T650QVF06.0
TABS:
- T650QVN04.0 XR1 65T39-S01
- T650QVN04.0 XR1 65T39-S02
- T650QVN04.0 XR1 65T39-S02
- T650QVN04.0 XR1 65T39-S04

flash W25X40CL

[xfox]

Re: Vizio M65-C1 no picture

Update: When I'm disconnecting one of right ribbons from tcon to lcd, I can see flickering picture on left side (half of screen)

[xfox]

Re: Vizio M65-C1 no picture

One more update: when I blocking SDO pin (goes to W25X40CL on lcd tab, I can see whole picture but it's flickering)

[xfox]

Re: Vizio M65-C1 no picture

After removing W25X40CL picture flickering, all pins in ribbon connected

[Nick's Tvs]

Re: Vizio M65-C1 no picture

I suggest heavily heating the heatsink with hot air and seeing if that makes a difference.

[xfox]

Re: Vizio M65-C1 no picture

I suggest heavily heating the heatsink with hot air and seeing if that makes a difference.

What kind of heatsink? I have working mainboard, few of them

[Nick's Tvs]

Re: Vizio M65-C1 no picture

I must admit I didn't notice the part where you said you got picture after removing the IC flash from the address board. However I have to stress that because the main board causes almost all of the distortion issues that are experieced with this type of Tv are you sure your main board is 100% good. It is extremely rare to see a bad panel or failed T-con. 99% of the time the main board is at fault for this model.

Also if you could show us pictures of what you are seeing that would help us understand better. I mean both the picture displayed on screen and the IC flash you say you removed that alows for picture to work which I am a bit confused about. In my experiencing removing that IC means no picture what so ever.

[xfox]

Re: Vizio M65-C1 no picture

Yes, I have two different tcons (working) and few mainboards, also working, so problem is definitely IN LCD, also without W25X40CL VGH is jumping up and down from 10V to 20V with chip it's stable 22V.
Picture I would say blinking (not leds), I was able to read dump from W25X40CL so it's working, also tried different one erased and with same data, same result. If somebody can dump W25X40CL from same TV, would be great

[Nick's Tvs]

Re: Vizio M65-C1 no picture

Okay I think something worth noting here is that the picture you sent of the screen is displaying the logo perfectly. Meaning that the distortion is occruing behind the logo.
Now if you keep running the set for a while, do you see a left side VS right side be more affected or is the screen universally affected in the same way?
What if you connect and HDMI cable and play a move from a DVD or cable box through HDMI, is the picture affected differently than say the menu?

[xfox]

Re: Vizio M65-C1 no picture

Universaly, yeah picture is perfect, but not background, I think it's because without spi flash VGH is pulsing

[Nick's Tvs]

Re: Vizio M65-C1 no picture

okay, so removing the W25X40CL from circuit allows for the screen to display picture, but also affects the picture quality.
My theory is that the IC flash is detecting a fault on one of the address boards then and is preventing the screen from powering on. With it disconnected, it's allowing everything to turn on and you have essentially turned off the alarm, but the problem is still there. At least that's the theory. Now when it comes to panel failures, the usual suspects are diodes and caps being shorted.
Have you checked your address boards for shorted caps and or diodes?
100 ohms would be considered shorted, so using the beep mode on your meter won't work as it won't beep above 50 ohms. I have seen a 65" sony recently show up with a shorted cap at 113 ohms.