Vizio 40” V405-H19 has backlight, no display

[mattd1979]

I have a Vizio TV that I am trying to fix for a friend. The problem is when you turn it on, you get a back light but no picture. If I press the input button one time on the remote, I will hear music. I ordered and replaced the main board as well as the power board from Shop Jimmy but no change. Any ideas on what else I can try to get a picture? The TV is a couple of years old.

Thanks in advance,

Matt

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

Bad t-con

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

Is there anything I can do at the component level to fix it? The T-CON board to LCD ribbon cables are bonded to the LCD.

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

Need some good pictures of t-con, and other boards

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

I have attached 4 photos. One wide shot and 3 up close shots of the T-CON board.

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

First check your white fuse where ribbon cable comes in for 12v on both sides. I can't see other voltages with these pictures.

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

Are you referring to the little white chip to the lower right of the connector in the photo on the T-CON board?

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

Yes. And only need good pictures of t-con board.

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

I tested the resistance on the fuse and it is at .02 ohms.

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

Do you get 12v to the fuse when tv is on?

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

Yessir I get 12.64 volts at each end of the fuse next to the ribbon connector.

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

On picture 5 you have a VGH and VGL test point you can measure.
You might also try disconnecting the 2 interconnect ribbon cables at picture 3 and see if you get half a picture.

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

I recently tried disconnecting the ribbon cables as you said but it didn't make a difference. What should the voltages be on the VGH and VGL test points?

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display


Readings are the same when unit is on or off.

VGH = .793 V
VGL_AA = 1.156 V
VGL_GOP = 0.00 V

[dskall]

Re: Vizio 40” V405-H19 has backlight, no display

So those are bad. Maybe best thing you can do is check the brown caps for shorts.

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

Which ones are the brown caps and how do I go about testing them?

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

The only capacitors I am familiar with are the cylindrical capacitors and I don’t see those. I see very tiny chips. Some are tan and some are dark brown that seem to vary slightly in size. Are those capacitors?

[nomoresonys]

Re: Vizio 40” V405-H19 has backlight, no display

some of them are, look closely at the designator beside the component, if it's a cap it will start with a C.

[mattd1979]

Re: Vizio 40” V405-H19 has backlight, no display

I just finished checking resistance on all of the capacitors I could find on the T-CON board and the readings ranged from 550 ohms to 30.00 k ohms.