Vizio 32 inch (VA320M) Eco 1080p black screen

[KuDaH]

Eco 1080p 32 inch Vizio
Model # VA320M

Picture went black, sound too. As the unit is powered on the vizio logo on the bottom goes from Amber to white. The Vizio logo on the screen pops up (black and white splash screen) and looks perfect. It stays on for about 5 or six seconds as usual, then goes black, this is all normal. From that point on I get nothing. Menu button does not produce an on screen menu, and input button does not display input selections. Video input from Direct TV is black and no sound. Direct TV box workls good on alternate TV.

Took the back off the TV. All the CAPS look good on three out of the four boards. Fourth board has no CAPS, Learning here myself... the power supply board voltages are ok on the outputs marked.. 24V 5V 12V and so on. I am not versed in advanced electronics but know the basics.

The inverter board looks good with its caps, all parts look good to me.

The small control board looks ok too.

The "Motherboard" I call it with all the inputs for audio and video also looks ok to me.

The TV worked fine, had a few times when it went black, but a restart fixed it. Now / No / Go.

Any help would be appreciated. already bought a new TV but would like to get this fixed.

[budm]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

"the power supply board voltages are ok on the outputs marked.. 24V 5V 12V and so on."
OK, do you have Digital meter? We need to see what voltage you have on those pins when you turn the TV on.

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

The voltages on those pins correspond to the voltage marked on the board. I checked them with the multimeter...all look good. I did not check the "ground" pins. Also unsoldered one lead on the fuses on the power supply board and checked continuity on them.. believe there are 5.. all read good.

[budm]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

Is there any label on the pin with BL_0N, Dim, or 'A', 'B'? I am looking to see if the BL_ON (Backlights On) signal from the main board goes away or not. By the way are the backlights still on?

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

There is a white wire on the output side of the power supply leading to the inverter. (that is the board with the side lights, I think is is called the inverter) its the big board that runs from top to bottom onthe left in the picture. The white wire says "On / Off" and yes the lamps shut off after the initial splash screen.

Good point, If that is the power to the lights.

I imagine I should get a reading off that and see if it is correct.

How do I do that?

[tom66]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

This one doesn't use an inverter.

But you said you lost sound?

Can you get close up of the power connector from PSU to main board?

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

Thanks, and yes loss sound too.
here is the powersupply close up

here is a close up of the connector on the power supply to the main board

here is a pic of the main board connection from the power supply


this should help

[tom66]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

OK, there's a pin marked 5V. Connect your multimeter's negative lead (black) to the chassis -- this is ground. What voltage do you measure on the 5V wire -- any one will do (not important which.) Probe the slightly exposed metal contact around the wire.

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

Done,

4.98 dcV on one
4.97dcV on the other

[tom66]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

OK, good standby voltage. Can you check 24V? If it drops out just as the Vizio logo goes away, this might be the problem.

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

Both 24v pins stay at 24v afterthe splash screen cycles and the lights go out.

[tom66]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

OK, now can I get a picture of the connector going to the inverter. We need to check if BL ON is going out. If it is, the main board is turning the backlights off. Vizios have lots and lots of problems with main board faults. I don't even work on them (US only) and I know that just from reading on here...

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

Picture of connector leading to inverter

sorry bad post here

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

Picture of connector leading to inverter

[tom66]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

OK, on this model it is ON/OFF, does the voltage change as the backlight switches off?

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

on/off lead readings...

.2mv TV off

4.92 V TV on

93.7mv after splash screen dissappears and lights go out.

[tom66]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

So the problem is on the main board. What a surprise...

Is it possible to remove that metal shield covering the inputs on the main board?

When you do that, follow retiredcaps excellent guide on testing your voltage regulators.
https://www.badcaps.net/forum/showpo...29&postcount=1

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

Im confused.

the on/off wire comes from the power supply and goes to the inverter. it gets its signal from the main board through the power supply?

[tom66]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

Yes, it is a common arrangement. The signal is passed from the main board, through the power supply, to the inverter, to reduce the need for more cabling looms (which costs money...) The power supply just has a direct connection between both ends. Same for DIM.

[KuDaH]

Re: Vizio 32 inch (VA320M) Eco 1080p black screen

thats why I am asking someone who knows what they are talking about.
I bever would have thought that. Thanks. gonna check out that link now. shield is off the main board now.