Vizio VX32L turns on with backlight, no video or sound

[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.

[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.

[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

[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.

[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

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.

[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.

[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!

[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. ;-)

[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...

[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.

[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?

[retiredcaps]

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

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

1) Post clear focused pictures of your main/logic board following my sig file below exactly. Manufacturers can and have made minor changes to the board.

2) See my sig file below on how to report the readings for voltage regulators. We can't tell if the above is good or bad without the component part numbers.

[budm]

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

"U8 3.3 2.2 0.4" U8 shows strange reading, if the voltage between the output pin and the adj pin is 1.25V, and adj to ground is0.4V, then the output pin with ref to ground should be 1.25 + 0.4 = 1.65V which is typical voltage either. Please check and see if you do have 1.25V between output and adj pin. Do you P/N as printed on U8?

[Andrew M]

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

These were all AMC1117 ICs- I was getting these readings before I swapped U7 and U9 out. I replaced them with AP1117E18GDICT-ND (from digikey).

U9 is 3.3, 2.2, 0.4
U8 is 5.1, 3.3, 2.0

I messed up when typing those in before and missed a line.

I also checked U15 and am getting 5.15 in and 5.05 out, and I checked the fuse on the T-con board (I'm assuming that's what it was- at the top of the set under a few layers of metal) and it was good.

Thanks for your help.

[budm]

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

Is U9 really 1.8V fixed LDO? Just want to make sure, otherwise 2.2V output is correct (1.8 + 0.4 = 2.2).

[retiredcaps]

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

These were all AMC1117 ICs- I was getting these readings before I swapped U7 and U9 out. I replaced them with AP1117E18GDICT-ND (from digikey).

If the originals were AMC1117 (adjustable regulators) and you replaced it with AP1117E18GDICT-ND (1.8V fixed regulator), you have the wrong part.

Go back and re-read my how to test a voltage regulator guide.

[Andrew M]

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

Well, Crud. Live and learn...Another order to Digikey for the right parts.

According to the website, AP1117EGDICT-ND is adjustable one (correct me if I'm wrong). I'm 99.9% sure they were all the same AMC1117 chips on there. One didn't make it through the desoldering process intact, and the other was definitely an AMC1117.

I'm slightly confused however... some posts seem to indicate these chips should all be about the same 5.0, 3.3,2.0, but other posts have indicated U7 and U9 should be 3.3, 1.8 (keeps memory alive or something?). Which is correct? If you are telling me I got the wrong part, then they should all be 5.0, 3.3, 2. What am I missing?

[retiredcaps]

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

I'm slightly confused however... some posts seem to indicate these chips should all be about the same 5.0, 3.3,2.0, but other posts have indicated U7 and U9 should be 3.3, 1.8 (keeps memory alive or something?). Which is correct? If you are telling me I got the wrong part, then they should all be 5.0, 3.3, 2. What am I missing?

Reread point #1 in post #93.

[budm]

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

Adjustable 1117 LDO will have one resistor between the ADJ pin and Ground, one resistor between ADJ PIN and OUTPUT PIN. You can calculate the output voltage if you know the resistors values.
Fixed output 1117 LDO will have no resistor, there will be Ground pin, Output pin, and INPUT pin. In rare occation, they may put a resistor between Ground pin and ground to raise the output voltage as needed by the circuit.
See spec sheet so you will understand what the 1117 series LDO are.