Vizio XVT47SV Problems

rmcel

Estimable
Aug 23, 2014
4
0
4,510
I have a Vizio XVT47SV TV that is 3 years old. The other day it just went black, however the sound works fine. If you wait a while after turning it off, you can turn it on and it will work fine for 5 minutes and then the screen goes black again with sound fine. I have tried different inputs and all act the same. I noticed that the screen just faded away and then if you leave it playing with a black screen, every few minutes an image will appear on the screen, like a large circle of the screen will work and then fade out again.
I ordered a manual online and checked the PS board and all voltages are steady except the PWM signal which dips slightly when the screen actually goes black. All features work on startup for the 5 minutes before it has the problem so something has not died. It appears to be heat related and I have carefully used cold blaster to hit every component on all boards to see if it would come back to life. No luck. No caps appear to be bad (bulging,etc). The LED backlights stay on the whole time, even when the picture disappears.
I suspect the TCOM bard or the main board is the culprit. What is your opinion of the problem?
Thanks
Dave