Vizio VW42L hdtv10a No Picture

[pfgallo]

Hi All,

I have read many of the Posts on this Tv problem - cannot find one on what I am seeing or what to test further.

I gave the Yellow Standby and then White light on with the Front of TV.

Checked all Cap's nothing looks bad or nothing else sticks out as bad.

No 12 or 24 V on the Power Supply so looks like not coming on.

On the Main Board I have on Fuse F2 5.1 volts, on Fuse F1 no voltage at all on either side on this fuse.

I figure should see something on at least one side if Fuse was Blown.

So the Question is - Where to look next ?? or link to a post that can help

Thank you

[johnboy1313]

Re: Vizio VW42L hdtv10a No Picture

Please post good clear pictures of your boards, each connector on the board, and one of the entire assembly. We can't really help if we don't know what you're working on.

[budm]

Re: Vizio VW42L hdtv10a No Picture

F1 is fed by the switched 12V from the power supply board, it will be present when the power supply board gets the PS-ON signal to turn on the power supply.
So you need to report the DCV readings of each pin of the power supply connector that goes to the main board, you MUST put pin name and pin numbers for each reading so will will know what are missing.

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

Here are some pictures

The Power Board, Main Board and the Two Fuses F1 & F2

If need more please let me know what your trying to see so can focus on that area.

Thank you

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

OK Measured from Power Board Connector

PSON - 3.12v

12v all -0 v

SGND - all 0 v

5v - 5.19 v all three

A- 1.49 V

B- 2.89V

C - 0

[budm]

Re: Vizio VW42L hdtv10a No Picture

OK Measured from Power Board Connector

PSON - 3.12v

12v all -0 v

SGND - all 0 v

5v - 5.19 v all three

A- 1.49 V

B- 2.89V

C - 0

OK, so you do have PS-ON, now we need to find out if the PFC Voltage booster is working or not since the 12V/24V power supply require Boosted Voltage to work.
Check the DCV between the two legs of the main filter cap to see if it has close to 400VDC on that cap. Be careful you will be working in the deadly side of the circuits.

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

Yes - The Very Large Cap on top left has 400 v across it.

[budm]

Re: Vizio VW42L hdtv10a No Picture

OK, we need the P/N of the SMD SMPS IC601 so we can look up the spec sheet to find out if it does have VCC to run it.

Vizio 0500-0507-0450 (DPS-260HP A) Power Supply Unit.
http://www.shopjimmy.com/vizio-0500-...wer-supply.htm

Pictures provided by shopjimmy.

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

Find IC603 on the board upper top middle and three lower bottom middle.

Do not see a IC601.

Can you give me a idea where to look?

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

Dla001d

917y736

[budm]

Re: Vizio VW42L hdtv10a No Picture

http://www.datasheetcafe.com/dla001d...controller-st/

Check the Voltage between pin 10 gnd and pin 12.

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

To do this I need the board to be removed from Frame and hanging free.

To get to the back IC

Is this OK to do powered up?? Board not grounded then to frame

Also the picture I sent of the IC which Letters are those pins near.

Want to make sure I measure correct ones

Thanks

[budm]

Re: Vizio VW42L hdtv10a No Picture

You can solder two wires to the pads and connect the wire to the dcV meter, you should leave the board mounting in place and you will need to have the main board connected to the power supply board.
Or you can use 470~1K resistor 1/4W (or larger does not matter) resistor between 5VSTBY and the PS-ON pin to force on the power supply so you can test the board by itself without having other boards connected to it and without mounting the board to the chassis.
You will be making the measurement in the HOT side so do not touch anything with your hands or body.

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

Ok

Your saying I connect wires to pin 10 and 12 and remount board with wires out back so can measure them.

For the ground can I touch any ground point or has to be the one you marked so then would need three wires out back

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

Looking at the IC its going to be hard to solder wires to it being so small

I got a 1 k Resistor and can do the second one.

So what is exactly you want me to do.

Connect resistor between 5VSTBY and the PS-ON pin and then ??

[budm]

Re: Vizio VW42L hdtv10a No Picture

Ok

Your saying I connect wires to pin 10 and 12 and remount board with wires out back so can measure them.

For the ground can I touch any ground point or has to be the one you marked so then would need three wires out back

Pin 10 is the GND pin for your black probe, pin 12 is the VCC for your Red probe.

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

Hi

Maybe did not read my last message ---

Looking at the IC its going to be hard to solder wires to it being so small

I got a 1 k Resistor and can do the second one point you said.

So what is exactly you want me to do.

Connect resistor between 5VSTBY and the PS-ON pin and then ??

[budm]

Re: Vizio VW42L hdtv10a No Picture

Hi

Maybe did not read my last message ---

Looking at the IC its going to be hard to solder wires to it being so small

I got a 1 k Resistor and can do the second one point you said.

So what is exactly you want me to do.

Connect resistor between 5VSTBY and the PS-ON pin and then ??

If it is hard for you to solder the wires so you can check the DCV between pin 10 and pin 12 then what else do you think you can do to accomplish that.
Once you install the resistor to simulate the PS-ON signal (so you can run the board by itself without having it connected to other board) then you apply AC power to the board and see what DCV you have between pin 10 and pin 12 of the IC for it to work.
Or instead of wasting time you can buy a replacement board.

[pfgallo]

Re: Vizio VW42L hdtv10a No Picture

Hi

I replaced the Power Supply Board and still did come on.

So today replaced the Main Board and again still does not come on.

Anyone any ideas??

Thank you

[budm]

Re: Vizio VW42L hdtv10a No Picture

Recheck and see if all the DCV and the command signals are present from the new boards.
i hope you bought the boards from good seller.