Vizio VW42L Black Picture Great Sound - Side Buttons don't Work except Power and Inpu

[DaveWein]

I just bought a "Master" Backlight inverter bord and replaced it. I still have the same problem. No Picture although the light on the front has power. I have great sound and funny thing is that the Power button and Input Button seem to be the only buttons that are working.
I have tried all the different Inputs as someone recommended and nothing. I have not checked the T-Conn bord or the fuse as someone else has recommended. Has any one else had this problem?

[bmadbob]

Re: Vizio VW42L Black Picture Great Sound - Side Buttons don't Work except Power and

Most likely it's the main board. The voltage regulators go bad sometimes. If you have a meter you can check them out. I think U33 is normally the bad guy. If I remember right it should have 5.19v in and 3.3v out.

[david37g]

Re: Vizio VW42L Black Picture Great Sound - Side Buttons don't Work except Power and

Is the backlight on? The screen will be light blue, the light can also be seen thru hole in the back of the panel. If it is on either the main board or the T-Con is probably bad. If it is off,and the master inverter was new, the slave inverter would be the next place to look. Check to see if the fuse is blown (small ceramic with brass end caps near cable connection). If it is blown the mosfets and controller should be replaced. Kits are available on eBay. Service manual listed elsewhere in the forum will give voltages on the main board DC-DC section so it can be checked.

[uberplasma]

Re: Vizio VW42L Black Picture Great Sound - Side Buttons don't Work except Power and

I had a similar problem on a samsung (known to be good), the problem was the power button was stuck in it's travel slightly, a large round button which traveled about 2 mm in a slightly larger hole, which caused the other buttons not to function, and the tv did not display any error codes, just hung in the wanting to power up state, the fix was to clean and lubricate the button itself and the holder, for lack of a better term, which the button travels in and all button functions returned to normal and TV works fine again, might want to check the switches for proper release

[Raven1776]

Re: Vizio VW42L Black Picture Great Sound - Side Buttons don't Work except Power and

I have the same problem with the button issue. But i need to know if u33 was the mainboard.if so i found mine but dont know where the input,output pins are and dont know where to put the negative probe at. Also when i have tinkered with the buttons and got them to function again. I still have a right half screen blue vertical line hue going on. I have already taken a t-con board from another same model and tried it to no avail. My next question makes me wonder about the t-con though. Are the main boards compatible if the board numbers are the same except the last number. They are the same tv model's.