Vizio VX32L turns on with backlight, no video or sound

[Andrew M]

Re: Vizio VX32L turns on with backlight, no video or sound

I'm stuck. I've read through the posts on this. I too have a Vizio VX32L with the backlight on, but no sound, no picture. I turned the TV off via remote control, and the white light stayed on, but the picture turned off. Since then, I can only power it on, and must unplug it to get it to power off. From the sound of it, the problem is U7 or U9 or U33. I replaced U7 and U9 and get the voltages below:

IC Top Mid Bottom
U7 3.3 1.8 0
U8 3.3 2.2 0.4
U33 5.0 3.35 2.1
U2 5.1 3.3 2.0
U4 5.1 3.3 2.1

the power supply is putting out 5, 12, and 24 volts on the appropriate leads.

I checked both fuses on the MB and they are good. I ordered a 1513 (U5) from digikey at the same time, but I have not replaced that (not sure how to test it), but am not even sure that is the problem...don't want to go there if I can avoid it.

The symptoms are still the same- backlight with no picture/sound.
Any thoughts?

[zylcho]

Re: Vizio VX32L turns on with backlight, no video or sound

Thank you gentlemen. Once again proves that this is one hell of resource. My 32l lives! U33 replaced, total cost $2.50.

[kevinm34232]

Re: Vizio VX32L turns on with backlight, no video or sound

Ugghh tried a TCON board off ebay, now instead of a slow white glow screen backlight comes on but still no pic, then shuts off after a bit. I thought it was going to work when I didn't see the white screen but now Im not sure if it's another bad tcon board or something else...

[DakotaKid]

Re: Vizio VX32L turns on with backlight, no video or sound

I fixed one of these sets that had following symptoms. Plug in and get orange vizio logo. Turn on power and logo turns white. Then, nothing works and set has to be unplugged. I found a bad SMD LDO 1117 at U8 or U9 or U33 or something like that on the mainboard. It's a low dropout voltage regulator that had failed. Seems there were about 5 or 6 of them on the board so it wasn't that hard to find. Once I replaced it the TV worked like new and still is almost 3 years later. It was well worth the 49 cent fix. ;-)

[woodyfl]

Re: Vizio VX32L turns on with backlight, no video or sound

Dont worry I wont junk it. My girls only wish that was my style. Come to my house and see the junk everywhere!

I will save it like I do everything. TV boards are so plentiful and cheap. I have boards from my optical lens grinding machines common in my industry used to control stepper drive machinery which have a very small market but sell as individual boards even used for more than most complete HDTV's

Thats what i really need to tackle!

[tom66]

Re: Vizio VX32L turns on with backlight, no video or sound

Put it up on Craigslist for $30 someone will take it and may fix it.

[selldoor]

Re: Vizio VX32L turns on with backlight, no video or sound

Ok - If your giving up on it dont junk it either keep it for parts or offer it for parts there is a classified forum on here or freecycle it - someone might want it.

[woodyfl]

Re: Vizio VX32L turns on with backlight, no video or sound

Yes I got a reading of no resistance all around the base of the fuse holders of F1 And F2. I am still hoisting the white flag my good man. My first attempt at board repair certainly wont be trying to revive this poor Frankenstien!

[selldoor]

Re: Vizio VX32L turns on with backlight, no video or sound

That is a shame anyway just as one last try how about seeing if the "repair"
is actually good. The joint may have become cold. Easy ohms test
across the ends of the OLD fuse not the solder blobs. Also if the rest of the repair involved changing caps based on what they did to the fuse they have probably used caps that are not suitable. If you can tell if they replaced any we will be able to tell you if they are likely to be any good.

[psmedley]

Re: Vizio VX32L turns on with backlight, no video or sound

I keep coming back to this - there are loads of caps on that board I have a small faulty tv with a similar number, perhaps more, and I just cant get my mind round replacing them all.

Me neither with my Soniq - hence I measured them all with an ESR meter and only replaced the ones with high resistance, and now the set works

[tom66]

Re: Vizio VX32L turns on with backlight, no video or sound

Hah! How cheap is a bloody fuse? That's a fire hazard there... ever seen a smoking SMT transistor, not pretty, but also damn flammable! So, who knows what else has been damaged by the incompetent idiot with the soldering iron.

[woodyfl]

Re: Vizio VX32L turns on with backlight, no video or sound

Thanks selldoor, killian, retired caps, tom and vince for the advice.

I finally located the fuses. she said it went bad once before and a local repair shop fixed it for $150. It worked for a couple of months then died again

Check out part of the fix- a fuse bypass on the F2. Nice work. I only took 1 year of high school electronics 35 years ago but old Mr. Stan Day never reccommended that method of repair. I will never forget bad boys rape our young girls......

I think I will end my short career as a board repairman here, anything past a blown fuse is beyond my patience and skill set. i will continue to use this forum to trouble shoot in which boards the problems lie and checking obvious problems like fuses and burned and bulging components.

Thanks again to all who tried to help me.

[killian6pk]

Re: Vizio VX32L turns on with backlight, no video or sound

SellDoor is correct there are several versions of that Regulator Package (how it looks) Some have 3 legs and some have only 2 legs soldered with the middle leg cut off. In that case usually the wide metal tab at the top takes the place of the middle leg. I found a datasheet for this Regulator (not sure it is the exact same). It should give you some idea about these and their different packages.

http://pdf1.alldatasheet.com/datashe...X1084-1.5.html

Also on your Fuses they should be small white surface mounted (soldered on each end) and be marked as F1 and/or F2. Often there is written on the board the Amps and the Voltage of the Fuse. You can check them with a Digital MultiMeter set on Ohms with a probe on each end the DMM should read no more than 0.1 ohms. If it reads more than that the Fuse is probably bad. Good news is that they are cheap as are most of the other components on the board. Find the Fuse or Fuses and report back the Amps and Volts you got.

[selldoor]

Re: Vizio VX32L turns on with backlight, no video or sound

"I just want to be clear where we are going and make sure if we get there i am capable of completing the tasks"

OK we can explain things at whatever level is needed.
Obviously we cant do the soldering or testing but can give step by step instructions. Whilst the set will be connected to the mains and on, most of the measurements will be low voltage so as long as you are careful to stay away from the HIgh voltage (Hot) side of the board except when guided to do so, you will be ok. I guess it was just a saying but drink and fixing electronics tend not to go well together.
Is your soldering iron electric and what wattage is it? 40 is often best. If you have time practice - just on any old bits of wire or electrical item. Similarly with your meter - practice on different setting check battery/cells car battery fuses bulbs power adapters - anything. It all helps you to get used to holding the probes and looking at the meter.- When it comes to the board checking there are two good rules.
Measure resistance = Power OFF
Measure voltage = Power ON.

You can get some practice on this board just measure resistance of various components and at the same time learn the board descriptions and what they look like.

Getting to the component in question, it is not fried-it is not meant to have 3 legs connected. The centre leg is meant to be cut off short, so that is why I suspect as it is not burnt it will be ok.

Unfortunately many of the tests to try and find the fault on the board rely on voltages and signals it receives from the other boards so it has to be connected.

It would be great if you tried to fix this as there are a lot of reported problems with this set and at least in your case it seems certain a problem on this board. If we can fix it then it will be something to help others in the future.

[woodyfl]

Re: Vizio VX32L turns on with backlight, no video or sound

The board is not hooked up to the TV yet again. I just want to be clear where we are going and make sure if we get there i am capable of completing the tasks. i havent used a soldering iron since the 70's. So are exploring the possibility that that component is still good and some how the connecting wire just got fried? If so for me it would be easier to just repair the connection while the component is out of the TV. I am a little nervous about testing voltages on a live board. I will probably need a stiff drink to steady my hand and then thats not such a good idea as well obviously. I am just being frank here I'm not a technician, I learned that years ago. Thanks for your patience. And I appreciate your trying to help me.

[retiredcaps]

Re: Vizio VX32L turns on with backlight, no video or sound

Oh ok D for diodes that explains the arrows.

http://en.wikipedia.org/wiki/Electro...e_designations

[tom66]

Re: Vizio VX32L turns on with backlight, no video or sound

What are the voltages on the pins of that device? Check with the black probe in a spare screw hole and the red probe on each pin in succession (except the chopped off one, include the tab/fat pin at the top.)

[woodyfl]

Re: Vizio VX32L turns on with backlight, no video or sound

@woodyfl perhaps we could make relevant suggestions if you were to update your profile with at least your country and while your in there mains voltage



Have you tested it - doesnt look burnt or anything

Ok I fixed it. Here we get 110 to 115v at 60hz. no I didnt test it I am not really sure how to do that. I was assuming that it wasnt supposed to look like that. it was my impression most of these components were very low priced if one could find them.

[selldoor]

Re: Vizio VX32L turns on with backlight, no video or sound

@woodyfl perhaps we could make relevant suggestions if you were to update your profile with at least your country and while your in there mains voltage



Have you tested it - doesnt look burnt or anything

[woodyfl]

Re: Vizio VX32L turns on with backlight, no video or sound

I cant seem to find out what is the equivalent of the U10

CAC 1084 0721 NL regulator? I guess

Where can one purchase this? Thanks in advance