Vizio SV320XVT no video no sound

[ruben53]

Re: Vizio SV320XVT no video no sound

What is the IC number (OZ9966?)

IC number---0Z9966SN

[dick_barton]

Re: Vizio SV320XVT no video no sound

If you short out the capacitor connected to Pin 15 of the OZ9966 and then power up the set do the backlights come on. Do as a quick test only.

[ruben53]

Re: Vizio SV320XVT no video no sound

What is the LCD panel P/N? LC320WUD-SBT1???
The STATUS (LAMP STATUS) test pad may give a clue.
Per spec sheet:
Normal : Low (under 0.7V) / Abnormal : High (upper 3.0V)
Agree that it can be the Transformer, CCFL, PWM IC.

http://www.shopjimmy.com/lg-6632l-05...t-inverter.htm

Attached the picture of the sticker on LCD panel

[budm]

Re: Vizio SV320XVT no video no sound

I would check that STATUS test pad to see if it shows abnormal DCV after the BACKLIGHTS go off.

[ruben53]

Re: Vizio SV320XVT no video no sound

I would check that STATUS test pad to see if it shows abnormal DCV after the BACKLIGHTS go off.

I turned on again and this time the tv turned on with nice video and sound.
when checked the status pad was 0v and trying to check other volts the backlights went off and the Status voltage again is 5v.
That means that inverter board is the problem?

[budm]

Re: Vizio SV320XVT no video no sound

The STATUS is for LAMPs Error according to the LCD panel spec sheet, but if the LAMP drive circuit is malfunction then I expect to get error too, but I am not 100% sure because I do not know the circuit is setup to dectect the lamp error, you may need to get the spec of the IC on that inverter board to find out, or may be bad solder joints on the inverter transformers legs?

[ruben53]

Re: Vizio SV320XVT no video no sound

The STATUS is for LAMPs Error according to the LCD panel spec sheet, but if the LAMP drive circuit is malfunction then I expect to get error too, but I am not 100% sure because I do not know the circuit is setup to dectect the lamp error, you may need to get the spec of the IC on that inverter board to find out, or may be bad solder joints on the inverter transformers legs?

I heated all solder joints of both transformers of the inverter board but still same problem.

[budm]

Re: Vizio SV320XVT no video no sound

Do you a way to test the capacitor ESR and capacitance of those lytic caps on that inverter board?
I would try new inverter board at this point unless you want to take the panel apart which is more chance of damage to the panel to find out if the lamps are bad or not.

[ruben53]

Re: Vizio SV320XVT no video no sound

If you short out the capacitor connected to Pin 15 of the OZ9966 and then power up the set do the backlights come on. Do as a quick test only.

It took me time to figure out how to short pin 15 of the 0Z9966 without touch
any other pins,finaly I did it and backlights come on and able to watch tv with
sound as long as its shorted if I remove the short backlights turn off and only
get sound no video.

So what that means?

[budm]

Re: Vizio SV320XVT no video no sound

That means the IC did detect lamp fault (Drawing too much current?) so it goes into safety shutdown.

[dick_barton]

Re: Vizio SV320XVT no video no sound

When you shorted pin 15 did you notice if any of the lamps failed to illuminate.

[ruben53]

Re: Vizio SV320XVT no video no sound

When you shorted pin 15 did you notice if any of the lamps failed to illuminate.

I think all the lamps turned on you can watch tv normally.

[Agent24]

Re: Vizio SV320XVT no video no sound

If one lamp is out you may not notice it from just watching TV. You'd need to check at the back of the panel

If all the lamps DO work fine, then maybe it's a fault in the current sense circuitry?

[ruben53]

Re: Vizio SV320XVT no video no sound

If one lamp is out you may not notice it from just watching TV. You'd need to check at the back of the panel

If all the lamps DO work fine, then maybe it's a fault in the current sense circuitry?

Checking from the back of tv I see a lot of lamps on but there are some under the boards so is not easy to know if there is one lamp off.

[dick_barton]

Re: Vizio SV320XVT no video no sound

Look very carefully at the back at the inverter board where the tubes clip in and you should see a glimmer of light at each connection point.

[ruben53]

Re: Vizio SV320XVT no video no sound

Look very carefully at the back at the inverter board where the tubes clip in and you should see a glimmer of light at each connection point.

That's correct I can see light at each connection and through a hole in center of inverter and all corners of panel and all holes of the back of panel.

[dick_barton]

Re: Vizio SV320XVT no video no sound

You need to start using your ohmeter to start checking the components around the OZ9966 chip.
Can you post a photo nice and sharp of the OZ9966 chip showing the components around it.

[ruben53]

Re: Vizio SV320XVT no video no sound

You need to start using your ohmeter to start checking the components around the OZ9966 chip.
Can you post a photo nice and sharp of the OZ9966 chip showing the components around it.

OK to take a clear picture have to wait until tomorrow,so I will do it tomorrow.
Thanks for your help.

[ruben53]

Re: Vizio SV320XVT no video no sound

You need to start using your ohmeter to start checking the components around the OZ9966 chip.
Can you post a photo nice and sharp of the OZ9966 chip showing the components around it.

Attached picture of chip 0Z9966

[vinceroger69]

Re: Vizio SV320XVT no video no sound

if a invertor board is cheap i would probably try another one then if still having the same issues it may need replacement ccfl tubes you can always re sell on the invertor board if it does not fix the issue.