Vizio VT420M No picture

[landyboy]

Re: Vizio VT420M No picture

I found two regulators on the main board. Using the provided testing procedure. I believe the first one is testing good. The second one:
U702
903T63 L161
Pin 1 0
Pin 2 3.293v
Pin 3 5.115v

I am still attempting to find a data sheet for that one.

[tom66]

Re: Vizio VT420M No picture

It would appear that regulator is OK. There is also at least one regulator on the T-con board.

[landyboy]

Re: Vizio VT420M No picture

Ok using the provided procedure both of the regulators on the main board test good. I guess I will look for a Tcon board. Boards for this model seem expensive.

[landyboy]

Re: Vizio VT420M No picture

Tcon ordered I will post results once installed..

[landyboy]

Re: Vizio VT420M No picture

Tcon installed no change just a dark blue screen.

[tom66]

Re: Vizio VT420M No picture

It is either the main board or panel then. To find out which you will need an oscilloscope.

[landyboy]

Re: Vizio VT420M No picture

Unfortunately I do not have an oscilloscope. Any other way of testing?

[tom66]

Re: Vizio VT420M No picture

Have you tested all of the main board regulators? If not, do so.

If so, then there are very few things you can do without being able to trace the video signal through the TV from the main board to the LCD glass.

[landyboy]

Re: Vizio VT420M No picture

I found two regulators on the main board. Using the provided testing procedure. I believe the first one is testing good. The second one:
U702
903T63 L161
Pin 1 0
Pin 2 3.293v
Pin 3 5.115v

[landyboy]

Re: Vizio VT420M No picture

I have a bad feeling it may be a panel

[tom66]

Re: Vizio VT420M No picture

Second one appears good.
It can still be a main board problem e.g. bad firmware or some such.
Tab bonds can also cause this.

[mikeclarke]

Re: Vizio VT420M No picture - component cooler fix

I still have sound. Mine works when first plugged in for about 10 minutes then no picture but I still have sound. If I plug in back in again after 3-5 minutes it's still no picture. If I wait 30 minutes it will work again for 5 or 10 minutes.

After it fails if I unplug it and spray component cooler on the mainboard it works almost right away. I normally wait 30-90 seconds before I plug it back in.

I'm posting this pic to help me identify this part. What's inside this thing and what is it? Thanks for your help.

VT420M94501155
CBPF9D1KZ
LC420WUF (SB) (A1)

[wriver11]

Re: Vizio VT420M No picture

"how do you replace a VIZIO VT420M board".

[wriver11]

Re: Vizio VT420M No picture

"how do you replace a VIZIO VT420M t-con board".