Vizio VX32L No picture, sound, or backlight

[tom66]

Re: Vizio VX32L No picture, sound, or backlight

Possibly not, if they have an additional part code like -33. The readings you are getting are indicative of faulty regulators and the main board may be dead now. This is why I rarely recommend harvesting parts because when you can order a new regulator for $3 from digikey or another supplier it just ain't worth the cost of replacing a main board. The only time I will harvest a part is when I can be certain there's no difference (like no such variants of it), or if I have a manufacturer-provided BOM, but I've never done it before.

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

No other number, just 1117

The main board number is 3632-0102-0150. I'll post a picture in a few minutes.

[tom66]

Re: Vizio VX32L No picture, sound, or backlight

And the one before that?

(I'll post back in the morning. Bed time now.)

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

I bow to your superior knowledge. You are exactly right. I just pulled the board to compare it to one my buddy has and realized that it isn't the same regulator. Not even close.

[tom66]

Re: Vizio VX32L No picture, sound, or backlight

Get a new main board then, it's all I can suggest.

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

I'm just gonna toss this one. I can get a working tv, used for less than a new board.

[tom66]

Re: Vizio VX32L No picture, sound, or backlight

Shame, it could have been fixed... please at least advertise it on craigslist for $10 (with a note that it's been worked on before) so that someone can get it working.

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

The board is 150 bucks. I can't see many wanting to put that much into a hundred dollar tv.

[tom66]

Re: Vizio VX32L No picture, sound, or backlight

It is possible to reverse the damage with care. But whatever, it's not like it's going to increase landfill by much.

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

If it's fixable, I'd like to try to fix it. I'll need help though. The garbage man won't take electrical trash so it would never make it to the landfill. I'm sure someone will take it if I set it out by the trash.

[tom66]

Re: Vizio VX32L No picture, sound, or backlight

If it's truly beyond your skills, leave it to someone else.
Practice on a dead/spare motherboard, sound card, etc before the $150 main board.

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

Let me rephrase it. It the main board that I have now is fixable I'd like to try to fix it.

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

Ignorant question for you. There is still a pad for the large single pin on the regulator, I've seen it referred to as "north". There is also half of a pad for the output pin. Assuming everything else on the board is working correctly, can I just run a jumper from the adjust at U10(1.37v)?

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

Also, I've read through this post again, I hope my frustration with myself didn't come off the wrong way. I appreciate your help.

[tom66]

Re: Vizio VX32L No picture, sound, or backlight

No. Adjust needs to go to ground. As I said, I suspect more damage has been done. You fed 2.35V into a 1.2V rail. The CPU may be damaged. You also need to make sure the new regulator doesn't overheat so it must have a good tab pad (the one you refer to as north?)

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

I've been combing the net for a replacement board. I've found one with the same number as mine for a price I can live with. The only difference is mine is 3632-0102-0150(4b) while the other is 3632-0102-0150(4a). Does that make a difference? While I'm on the subject, any idea why there are so many different part numbers from the exact same printed board number all for the same vx32l tv#?

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

Couldn't find a surface mount 1117 voltage regulator locally, but saw that a 317 had the same outputs and Radio Shack stocks them. I figured I had little to lose so I bought one, added some jumpers and a heat sink and attached it to a piece of breadboard. I still need to find my heat sink compound and put the back on.





Oops, upside down.

[tom66]

Re: Vizio VX32L No picture, sound, or backlight

I have done that before on a Toshiba.

Looks like a nice hack, well done.

I am amazed the CPU took 2.35V.

Then again, I must relate a story from my workplace. We were using some Freescale ARM processors which have a known bug: the onboard CPU regulator (I think it's a buck converter using external components) fails, causing the 0.9V core to experience about 3.3V. Amazingly, the processor still worked with this failure, but tended to crash now and then, and got very, very hot.

[johnboy1313]

Re: Vizio VX32L No picture, sound, or backlight

Craziest thing. When I hook up a component to AV1 or AV2 I get sound and a blue screen that says no signal. I tried a PS2 and a DVD player. Any ideas?

[budm]

Re: Vizio VX32L No picture, sound, or backlight

Hey, great job, but I would replace it with real LDO regulator, the 317 may not even need the heat sink, just see how hot it feels.