Vizio vo42l No picture

[TimT]

Hi Everyone, I have a Vizio vo42l with no picture and no sound " i think " just trying to figure out which board to swap out.
The vizio logo is white and will stay white until power button is pressed then turns amber.

stand by is 5v and P-ON is 3.5v. p-on is always at 3.5v untill power button is pressed then p-on drops to 0 " vizio logo turns amber " the jumps right back to 3.5v vizio logo still amber.
this is the only time p-on drops to 0 and then its brief.. like one second. the 12v and 24v output from the power board is always 0. I am no expert just trying to figure out if the power or mainboard is at fault.

unfortunately im not near the Tv, so no pictures, thank you.

[dskall]

Re: Vizio vo42l No picture

May have to disconnect cable from main board and jump ps_on to ground through about 600ohm resistor and see if other voltages come up

[TimT]

Re: Vizio vo42l No picture

Thanks for the reply! will try this in the morning. I am having a hard time with the colors. I think this is 600ohm tests 0.66 on MM adding a picture, maybe someone with better eyes can tell.

will it need to be grounded to board? or chassis?

thank you

[dskall]

Re: Vizio vo42l No picture

If you disconnect cable at main board side you can insert leads into connector. There should be a ground on one or more of the wires

[budm]

Re: Vizio vo42l No picture

"stand by is 5v and P-ON is 3.5v. p-on is always at 3.5v untill power button is pressed then p-on drops to 0 " vizio logo turns amber " To me that PS-ON is active HIGH, not active low. I have never seen Vizio LCD TV uses active low for PS-ON.
The two fuses on the main board are good?
Also try disconnecting the inverter boards from the power supply board to see if the 12V/24V will come up.
There are more than one version of this TV model.

[TimT]

Re: Vizio vo42l No picture

Sorry guys, this was a user error. With the TV off the multi meter reads 0.35
my meter don't level out to zero. When you turn the TV on it jumps up to 3.5v

I did ground it with the resistor. That didn't make any difference

Safe to assume there's an issue in the power supply?

[budm]

Re: Vizio vo42l No picture

Did you test the stuff I indicated in post 5?

[TimT]

Re: Vizio vo42l No picture

I disconnected the inverter board it did not bring up the 12/24
Check the fuses on the main board . Top fuse 0.05 bottom 00.1 those are the actual readings on the multimeter. I Checked both ends of the fuses. Tested good for continuity

[budm]

Re: Vizio vo42l No picture

At this point we need good clear pictures of the whole back side of the TV showing all the boards and good clear straight shot of the top and the bottom side of the power supply board.

[TimT]

Re: Vizio vo42l No picture

After removing the power board there is obvious damage. Sorry about the quality of the pictures . I added a close-up of the damage . I will go ahead and order a new power board, I just hope it didn't take out anything else.

There was apparently a lightning strike near the house were this TV was at.

[TimT]

Re: Vizio vo42l No picture

Sorry, apparently I can't add images from my phone