Vizio 32" VO320E Intermittent Issues

[bahowe1]

Hello, first, let me say thank you for all the knowledge that I have already gained from all of you. However, after all my searching, I still can't find a similar problem.
I was given a Vizio 32" that did not work. I don't own a TV (yet) and have little (no) experience with LCD's but have messed with electronics for years. I can't figure out what's happening with this one.
When I plug it in and turn it on, sometimes - usually the first time after I plug it in, the backlights will turn on and the logo will turn white. No picture, but I am not sure if there is supposed to be one. I can also turn it off, the backlights will go off and the logo will turn orange. If I try to turn it back on, the logo will turn white, but backlights will not come back on. Sometimes I can unplug it and plug it back in and turn it back on, and the backlights will come on again, sometimes they won't.
I have done the following tests:
Large capacitor ON/Off: 405/167. It appears to look good.
Fuse 1 on Power board off - 0, on - 120VAC
Fuse on Main Board F1 5.19 on and off
Fuse 2 on Main Board F2 0-off, 12.21 on
Regulators - Off (first three numbers)/ On (second three numbers). Also, I should note that I tested the regulators when the backlights were working... should I test them again when they are not working?:
TU52
EH13A
928k80
0
0
0
.01
.42
.1

U2
L311
G1117
0
0
.47
2.05
3.3
5.04

U8
L311
G1117
0
0
0
.01
1.25
3.28

U9
L311
G1117
0
0
.47
1.26
2.51
5.04

U7
1084
0931gL
0
0
.47
2.07
3.31
5.04

U4
L311
G1117
2.06
3.3
5.19
2.06
3.31
5.09

U5
L311
G1117
0
0
.46
1.38
2.63
5.04

U11
7805CT
RAG930G
0
0
0
12.18
0
5.02

Board numbers are:
Main: 0171-2271-2846
Power: 0500-0412-0737

At the power Supply, when it says 5V, I am getting 5.18 in all locations, at the 12V's I am getting 12.18. The on/off is showing 3.18.

I am lost in how to move forward. Any help in pointing me to a correct direction/path would be much appreciated!
Thanks!

[Alastair E]

Re: Vizio 32" VO320E Intermittent Issues

Visio sets seem to have a bad rep as to Mainboard faults--whats causing the issue, I dont know.....
Some say corrupted F/W others say component failure.....

[bahowe1]

Re: Vizio 32" VO320E Intermittent Issues

Images of the two boards have been added... hoping budm can provide me some help?

[budm]

Re: Vizio 32" VO320E Intermittent Issues

U2 L311 G1117: OK, 1.25 Vref + 2.05 = 3.3
2.05
3.3
5.04

U8 L311 G1117: OK, 1.25
.01
1.25
3.28

U9 L311 G1117: OK, 1.25Vref +1.26 = 2.51
1.26
2.51
5.04

U7 1084 0931gL: Questionable, 1.25Vref +2.07 = 3.57 more than 3% off
2.07
3.31
5.04

U4 L311 G1117: OK, 1.25Vref +2.06 = 3.31
2.06
3.3
5.19

U???: OK, 1.25Vref +2.06 = 3.31
2.06
3.31
5.09

U5 L311 G1117:OK, 1.25Vref +1.38 = 2.63
1.38
2.63
5.04

U11 7805CT RAG930G: OK, it is 7805 5V Volt regulator
12.18
0
5.02

You should verify U7 again.

[keeney123]

Re: Vizio 32" VO320E Intermittent Issues

You may have already done this, but you might want to disconnect the cable going to your screen from your t-con bd. and reconnect it making sure it is completely in the connector before you lock it into place. Sometimes a magnifying light is useful for this. Yes, the white logo means that the TV is on and orange is that it is off. If the TV is on and you are not getting a picture then I would suspect of video problem. You should get either the set up screen or a input number.

[bahowe1]

Re: Vizio 32" VO320E Intermittent Issues

Budm - thanks, I will re-check U7. One note that I made while checking this one in particular was that there was no 'leg' from the regulator that went to the board for the middle pin. Is there supposed to be? I understand these regulators are connected internally - the tab and the middle pin, so when I tested the board, it had the same reading as the edge of the regulator where the 'leg' would have protruded from the regulator. You can barely see it in the picture that I attached. Does this leg have to be there if it has the big tab?

Keeney123 - thanks. I have not touched any of the connections, I will check that tonight. Thanks also for letting me know what I will see if it were working correctly - I had no idea what I should be seeing.

Thank you guys, I am really enjoying learning and am hoping to replace components when we eventually find the problem.

[bahowe1]

Re: Vizio 32" VO320E Intermittent Issues

Budm - am I missing something? U7 was showing 2.07, so I add the 1.25 and arrive at 3.32, and the middle pin was showing 3.31. Your post calculated 3.57. Could you help me understand?

[budm]

Re: Vizio 32" VO320E Intermittent Issues

Sorry, typo, should be 3.32 not 3.51.
So I would check the DC Voltage on the T-CON board fuse next.

[bahowe1]

Re: Vizio 32" VO320E Intermittent Issues

I will check the fuse on the T-CON board tonight. Did you happen to see my comment about the U7 regulator not having a 'leg' at the middle pin? When I checked the board at the solder area where the leg would have landed, it seemed to have the same voltage as the tab and also the part of the leg that was still on the regulator. You can see the missing leg in the picture (barely). It's attached above. Does this make a difference?

[budm]

Re: Vizio 32" VO320E Intermittent Issues

The Tab and the middle leg are tied together inside the IC.

[bahowe1]

Re: Vizio 32" VO320E Intermittent Issues

I think I checked the fuse on the T-CON board and have no power to the board. But, I wasn't sure it was the fuse because it wasn't labelled with a "F" but instead a "C". I took a picture. Can someone verify that the rectangular block right beneath the ribbon cable (sort of left of the middle of the ribbon) be the fuse?
If that was the fuse and I have no power, now what do I check?
I also disconnected the ribbon at both the t-con and the man board connection and reconnected to make sure it was correct - no change.
Also, does anyone know the part number for the fuse labelled F2 on the main board? The writing on it has like an 'L' with an 'F' inside it and a 5A.
Thanks
Ben

[keeney123]

Re: Vizio 32" VO320E Intermittent Issues

That looks to me to be a capacitor. It is labeled a C? I am not real familiar with this TV. This is where BudM has knowledge. I take it that the t-con board is on the board running on top of the screen and not on a separate board ahead of this board?

[budm]

Re: Vizio 32" VO320E Intermittent Issues

OK, you have one of those part of the T-CON is on the main board and part of it integrated into the panel assembly.
https://www.badcaps.net/forum/attach...0&d=1414053405
Do you see the round copper pad test points with VDD and VCC labels next to them?
Check and see what DC Voltage you get on those two pads.

[budm]

Re: Vizio 32" VO320E Intermittent Issues

"Sometimes I can unplug it and plug it back in and turn it back on, and the backlights will come on again, sometimes they won't. " What worry me beside not having pictures ont he screen, it seems to me you also have other problem with main board functions as well.
You may want to contact shopjimmy to see what they think, I believe you will need new main board.

[bahowe1]

Re: Vizio 32" VO320E Intermittent Issues

VCC on the T-Conn is 0.12. VDD is 0. Both were zero when I would plug it in and the backlights would not come on (even though the Vizio symbol was white). I could only get VCC to read something if the backlights would come on. I can contact ShopJimmy on Monday (looks like hours are only Mon-Fri). Any other ideas? Did that voltage check on the contact pad give any ideas?
Thanks for all your help so far!
Ben

[budm]

Re: Vizio 32" VO320E Intermittent Issues

"Did that voltage check on the contact pad give any ideas?" Yes, the main board is not sending out the Voltage.
I would send an E-MAIL.

[budm]

Re: Vizio 32" VO320E Intermittent Issues

OK, I just remember another VIZIO that I help another OP. there is a fuse for the T-CON section on the main board, fuse TF1, see if you get the Voltage on both end using chassis as the GND Ref.

[keeney123]

Re: Vizio 32" VO320E Intermittent Issues

Another thing you might what to try is once the backlights come up, take the connectors that are not one of the ribbon cable connectors and apply pressure first one side and then the other. Grab the insulated part of the connector making sure your fingers of hands do not touch any components and not a lot of pressure. See if you can get the backlights to go out.

[bahowe1]

Re: Vizio 32" VO320E Intermittent Issues

I checked voltage at TF1 when the backlights were on and have no voltage on either side of the fuse.

I also checked all connectors as kenney123 suggested and could not get the backlights to go out.

[ERICSSON89]

Re: Vizio 32" VO320E Intermittent Issues

then I think the main board might be the problem. can you replace the fuse with another to see if there's a change? and if not, suspect the mainboard is not getting a voltage.