Vizio VO42L Turns on by self NO Pic or Sound

[plafleursr]

I have a VO42L when you plug in the AC plug Vizio on front goes Orange then turns White. Can not turn off, no sound or Picture. Have checked PS have 12v and 24v and have 3.4 volts for turn on. No Back lights. Have looked at caps on all boards none look bad. No burns chips. Could main board be bad, as it looks like it controls on/off and sound. Have 5v & 12v to Main board fuses.

[lorins_core]

Re: Vizio VO42L Turns on by self NO Pic or Sound

Sir. would you try to Re-solder the Power supply. or can you check at Ohm-miter (tester) the Capacitor.

[vinceroger69]

Re: Vizio VO42L Turns on by self NO Pic or Sound

have you read this
https://www.badcaps.net/forum/showth...ht=Vizio+VO42L

[plafleursr]

Re: Vizio VO42L Turns on by self NO Pic or Sound

The power supply looks to be working as I have the 5volts, 12 & 24 volts po on is 3.4. As the tv when plugged in goes from orange to white by is self, I think is a main board problem. I think the main board controls the turn on for Backlights as the 24 volts are present at J1 pin 1 of inverter pcb.

[tom66]

Re: Vizio VO42L Turns on by self NO Pic or Sound

Sir. would you try to Re-solder the Power supply. or can you check at Ohm-miter (tester) the Capacitor.

What do you mean by this?
You can't use an ohm-meter to check a capacitor, except for leakage, which usually isn't a concern.

[budm]

Re: Vizio VO42L Turns on by self NO Pic or Sound

I would check the voltage regulators on the main baord first since we at least know that the 5V STBY is working.
Please upload the GOOD, CLEAR pictures of the main board using managed attachment.

[plafleursr]

Re: Vizio VO42L Turns on by self NO Pic or Sound

I would check the voltage regulators on the main baord first since we at least know that the 5V STBY is working.
Please upload the GOOD, CLEAR pictures of the main board using managed attachment.

Sorry No camara. What are the regulators numbers, did check the 5 volt one had 12 v in and 5 v out

[tom66]

Re: Vizio VO42L Turns on by self NO Pic or Sound

We really cannot help much without photos of the board, can you not borrow a camera?

[plafleursr]

Re: Vizio VO42L Turns on by self NO Pic or Sound

OK how do you upload pictures

[tom66]

Re: Vizio VO42L Turns on by self NO Pic or Sound

Do you see the manage attachments option under the reply to thread area?

[plafleursr]

Re: Vizio VO42L Turns on by self NO Pic or Sound





Ok Here are some pictures

[tom66]

Re: Vizio VO42L Turns on by self NO Pic or Sound

Good pictures, thanks.

I have highlighted the voltage regulators.

To check each regulator post the voltage on each pin relative to ground (chassis of TV) with TV in the malfunctioning state. Note the part number on each regulator e.g. UM1117-3.3, include the reference code near by e.g. U33.

[budm]

Re: Vizio VO42L Turns on by self NO Pic or Sound

And here are the pinouts you should use when you take the readings on all 3 pin of the LDO regulator.

Notes; the big tab on top is connected internally to the center pin.

[plafleursr]

Re: Vizio VO42L Turns on by self NO Pic or Sound

Taken with cheap volt meter. Made layout and took picture.

[tom66]

Re: Vizio VO42L Turns on by self NO Pic or Sound

Can we have part #'s (ex. UMC1117-3.3) for those?

[plafleursr]

Re: Vizio VO42L Turns on by self NO Pic or Sound

ok here they are: Took numbers off chips tried to look up.

U16 7805

U15 & U20 1084
0851KL

U17, 22,44,21 ? L032
G1177

[plafleursr]

Re: Vizio VO42L Turns on by self NO Pic or Sound

Chip pn 1084 second line 0851KL
L032 second line G1177

[tom66]

Re: Vizio VO42L Turns on by self NO Pic or Sound

Can you make sure that L032 is not actually "1117" instead, as that is a common part #.

[plafleursr]

Re: Vizio VO42L Turns on by self NO Pic or Sound

U 44 is 1117 the rest of that group are L032 G1117

[plafleursr]

Re: Vizio VO42L Turns on by self NO Pic or Sound

Bump