Vizio m601d-a3 backlight issue

[Mectronik]

Hello, I'm working on a Vizio m601d-a3 with a backlight issue that I am having a difficulty diagnosing it. As it sits, the tv powers on, displays the Vizio symbol and with nothing hooked up it will then display no signal but you can only see half of the screen. I know it's a back light issue because the picture is there without light behind it, as I can see it by doing a light test. I've taken off the paneling and done a visual inspection. If I disconnect the tcon ribbon cable to the affected side then the entire half of the screen goes away. I've checked voltages at the LED driver from the main board and from I can deduced the voltages are fine however I cannot figure out how to test the LED driver. I also can't seem to find any literature explaining test steps or a pin out, as the pins aren't labeled on the board itself.

I am an experienced automotive mechanic and have the tools I would need to diagnose and repair however I'm not as experienced in this field as much as I would like to be. I would also like to ask for any additional information to learn more about. I've seen the FAQ and found the PDFs however they are broken.

Thank you in advance.

[EazyBone]

Re: Vizio m601d-a3 backlight issue

Generally you can use a LED tester. They are a bit safer because if you short them it usually doesn't do any damage. Then you test the line to the lights and try and light them up. The tester will tell you if you have a short.

So just to confirm, the half of the screen with no light has the full picture behind it correct? It's not cut off exactly down the middle? If that's the case your LEDs are bad and you just need to replace them. If the power board is lighting up half and both sides voltages are the same (to rule out power board, which pretty much is already) on the power board then you definitely got a light problem.

LED tester would just confirm this, but you just need to replace them.

Lookup changing LEDs using shop jimmys videos. They will help you to learn. The whole tv has to come apart, and it's pretty easy to damage the screen/ribbons on the screen if you aren't careful so I'd watch them.