Its been in for a week. I have had no problems since the card was installed.
I have a different model Vizio then is titled in this forum. I have a VO370m but the symptoms were exactly the same. Lines across the screen and freezing(as pictured) depending on the heat and humidity , as well as time idle. The problem got worse with time(years) till Iit would take an average of 3-5 minutes for the TV to render an image, If it ever did, sometimes it would not work for days.
After installing the t-control board, MY TV started right up and immediately rendered an image.I got to seen a boot up screen I forgot even existed. I have not seen one line or had any delay since.
It is possible that the boards just go bad with time. I got a used one just to see if it would work.
I suspected it was the t-conrol board when i first opened it up since it is the gpu for the TV, responsible for rendering the image on the screen. It did not seem likely that it was the power supply since it always turns on reliably. I didn't think it was the motherboard or cpu( the Main Unit as you have called it on this forum) since all of TV functions and ports were working properly. So I was thinking it had to be the screen (not worth replacing $$) or the Graphic Processing Unit (T-control board) which is responsible for rendering the image on the screen.
To be clear this is the first TV i have ever worked on, but i am very familiar with computers and computer repair. What struck me when i first opened my TV was that it was just a very simple flatted out computer that was all screen and very little PC.
Anyway I found this forum and it did help me a lot in that it confirmed my suspicions since you guys had tried basically everything except replacing the T-control with no results. So if you have any questions or need any help installing it i would be glad to help.
This is the card I bought for my VO370m
This is the card you will need for the TV model Titled in this forum Vizio SV370XVT
New or used that's your Choice. I like to have a warranty either way, since we know these boards go bad. The longest i could find was 90 days tho so it might just be better to buy a used one every few years if it does go on you.
Thanks for your help everybody. It feels empowering to fix something new and not take part in our throw away culture!