Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

[johnboy1313]

Figured I document this for anyone else having the same issue.

Picked up a 42" Vizio VU42L yesterday. I went into Chicago (~60 miles) to pick up a 60" Sharp for cheap. On my way home, I get a call from a guy with this Vizio wondering if I'm interested. I have him text his address and he's just up the street from where I was parked at when he texted. That's great cause it helps split the cost of gas. I went and checked it out. It would power on with a good backlight. No pic, no sound. I didn't realize this at the time, but it wouldn't power off until it was unplugged.

I originally suspected a fuse on the T-con or a bad T-con altogether but when I realized there was no sound either, I focused on the main board. I pulled the cover off the main and, guess what?? U7 and U33 were both bad. Surprise! In the end, that was all that was wrong. I bought a bunch of 1117 regulators the last time I had a Vizio on the bench so I had the parts on hand. Replaced U7 and U33 and now I've got a working 42" 1080p Vizio.

[tom66]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Not bad! Surprising how common these voltage regulators fail, one of my most common fixes. I think I'm on my 3rd or 4th regulator going bad. One thing you can do if you're not 100% sure the regulator is bad is to freeze spray, often it will start working after a blast of cold.

(P.S. When's the 60" Sharp thread coming... :P)

[johnboy1313]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Soon, it's too big to move by myself. As soon as I can find a place big enough to work on it, I'll start a thread. I picked up an LG 42pj350 yesterday too. I think it's a main board issue as well. That thread will probably show up sometime tonight.

[Thomas Capper]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

I put up a post about my tv with a similar problem. It was bad regulators.

[HollyHill]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Where can I buy parts for the Vizio VU42LFHDTV10A main board? I still have good picture quality but the sound went out a couple of days ago and I would like to try and fix it myself before setting it out for trash .

U7 and U33, 1117 regulators

Thanks!

[tom66]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

You need full part # e.g. UMC1117-ADJ, AK1117-33, etc. Parts can be bought from eBay.

[HollyHill]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Actually I was just on eBay and found some main boards and found an image on google. Is this it (example)?
http://assets.shopjimmy.com/media/ca...4202820150.jpg

I found these on eBay: http://www.ebay.com/sch/i.html?_trks...=293&_from=R40

Would it be better to just replace the main board or is it just as easy and cheaper to replace the sound fuses/regulators? Will I need to solder something?

Thanks

[patrax]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Ive repaired a few of these too,and with that said caps on both inverter boards will be next on the list. The ones I did were so swelled and leaked so bad it was a wonder it didn't catch fire. U33,U7, and the rest of the LOD's should always be checked in any Vizio Lcd.

[HollyHill]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

I plugged in a Music Bullet that I purchased from the Navy Exchange some time ago, $15 and it worked. I plugged the Music Bullet into the back of the Directv satellite box, one end into the USB port and the other end into the white audio hole. It's a little loud and I cannot adjust the sound, but that's okay.

http://www.shopatasseenontv.com/imag...c%20Bullet.jpg

I still have plans to fix the sound on the main board once I find the right part(s).

I HAVE TV SOUND AGAIN!!!

[ny_jets_head]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Figured I document this for anyone else having the same issue.

Picked up a 42" Vizio VU42L yesterday. I went into Chicago (~60 miles) to pick up a 60" Sharp for cheap. On my way home, I get a call from a guy with this Vizio wondering if I'm interested. I have him text his address and he's just up the street from where I was parked at when he texted. That's great cause it helps split the cost of gas. I went and checked it out. It would power on with a good backlight. No pic, no sound. I didn't realize this at the time, but it wouldn't power off until it was unplugged.

I originally suspected a fuse on the T-con or a bad T-con altogether but when I realized there was no sound either, I focused on the main board. I pulled the cover off the main and, guess what?? U7 and U33 were both bad. Surprise! In the end, that was all that was wrong. I bought a bunch of 1117 regulators the last time I had a Vizio on the bench so I had the parts on hand. Replaced U7 and U33 and now I've got a working 42" 1080p Vizio.

What voltage should I expect at U7 and U 33 as well as the other 1117s on the main board. I have one doing exactly the same thing you experienced.

Thanks

[johnboy1313]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Test the voltages at each leg of the regulators. Black probe on a screw holding the board to the panel, red probe on the regulator leg. Record each regulator like this

U33 1117
Pin 1 X.XXV
Pin 2 X.XXV
Pin 3 X.XXV

where the X's are the voltage you measured with your meter set to DC.

[ny_jets_head]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Sorry for the late reply I forgot to subscribe to the thread.
I did a little reading on this and determined that the output on U33 was incorrect
I have 5.1 in and 2.1 on the tab and 1.3 on the adjustment pin
If i'm correct I should have 3.8 on the tab with it working correctly.
I ordered up a bunch of AS1117's and just waiting for them to arrive.

[tom66]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

You should have 3.3V on the tab. 2.1V is bad. Replacing it should work.
Odd how basically all of them fail and drop to 2.1V, versus other voltages.

[ny_jets_head]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Thanks !
I will post the out come once I get the parts.

[ny_jets_head]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

U33 was the problem up and running again.

[viziodad]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

OK, I checked, and no one here has my exact problem:
Vizio VU42L FHDTV10A;
No picture or sound..
No 12 or 24VDC. 5VDC is good. ..
.Power supply relay clicks when power button on side of tv pressed..
Replaced power supply..This one does not even click..
Put old one back in..
PSON pin reads 3.3Vdc..
Hope someone sees this, since I don't see how to start a
new thread..thank you...

[paknoy]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

you just fix my TV @ johnboy1313, I have the same model same issue. just happen to have a bad Vizio mainboard with at least 3 regulator 1117 took me 1hr 1/2 but worth to try and it works \../
thanks again

[johnboy1313]

Re: Vizio VU42LFHDTV10A, Good Backlight, No Picture, No Sound Fix

Glad to help.