Vizio E7-E3 Black Screen

[BobbyG58]

Re: Vizio E7-E3 Black Screen

"Not fully understanding why there is voltage going in but not coming back." That is still puzzle to me too.

Another thought.

When checking the voltage on the black, should that be ground to chassis and red probe to black wire or red probe to red wire and black probe to black wire? Maybe I am checking it wrong. I am checking all with ground to chassis.

[budm]

Re: Vizio E7-E3 Black Screen

Black probe on the chassis, Red probe on the Black wire.

[BobbyG58]

Re: Vizio E7-E3 Black Screen

Maybe check those little capacitors on tcon for shorts, diode mode, probe on each side, tv unplugged.

I probed ALL of the caps on the T-con.
Diode Mode, ground to chassis probe both sides of caps.
All caps read on both sides.

[nomoresonys]

Re: Vizio E7-E3 Black Screen

I probed ALL of the caps on the T-con.
Diode Mode, ground to chassis probe both sides of caps.
All caps read on both sides.

No, probe on each end of cap, not using ground in this measurement.

[BobbyG58]

Re: Vizio E7-E3 Black Screen

Ok, it has been awhile as I have been out with some health problems.

I am posting 2 photos, to try and determine what might be happening.

One is the photo of the LED Tester that I purchased that has a range of 260v.
The other is the lead from the Mainboard to the LED strips.

I have not disassembled the panel.

6 Red lead feeds approx 57v each to 6 rows of LEDs. 2 Strips per row and 9 LEDs per strip. (57/18=3.166v)

There are 12 black leads coming back for each strip.

I started with a black probe from the tester to a black lead on the connector, then I probed each of the red leads, expecting to see the LED tester to return a voltage of approx 28.5v. 3.166v*9LEDs per strip.

Instead I got 0v on all black leads and red leads. in all combinations.

Am I missing something or not understanding how to test the strips while they are still in the in the panel?

again, sorry for not posting on this in awhile.

Bob

[BobbyG58]

Re: Vizio E7-E3 Black Screen

1) As I explained how the LED strips are connected, you have 12 LED strings = 12 Return black wires, 1 wire is shared by two LED strings so that is why it has 6 red wires. Each LED string has 9 LED's and 12 LED drivers, each driver drives 9 LED's.
May be you need to invest in LED tester so you can test the whole LED string without opening the panel.

Hi Bud, can you please take a look at my last post and comment please?

Thanks,
Bob

[motterpaul]

Re: Vizio E7-E3 Black Screen

Hello all...

My first post here but I am not completely useless. I have never fixed a TV, but I do know electronics (guitar pedals, etc) and can use a DVM.

I also have a Vizio E70-E3 and I have a similar issue to Bobby G but different voltage issues.

On my Power Supply board, I have the correct standby voltage - 15V. But I have NO voltage going to the LED strips on this board and hence none on the mainboard. I tried disconnecting the main-board and remeasuring, but it made no difference in LED V.

NOTE: MY TV has only 4 LED voltage contact points on the power supply board and they each appear to control three half-strips (meaning there are 12 LED strips total, but they fit together to go across the entire TV, so it is like 6 long strips. So, it is somewhat odd that only half the two connected strips would fail, but that is what appears to have happened. Ther dead strips are arranged on screen like this.

xxxxxxxxx000000000
xxxxxxxxx000000000
xxxxxxxxx000000000
000000000xxxxxxxxx
000000000xxxxxxxxx
000000000xxxxxxxxx

I now think I need a new power supply board - but there is more to the story....

This project started with a complete LED strips replacement because 6 of the 12 total strips were dim.

Anyway - we put the TV back together after LED strip replacement, and it will not turn on. As I said, I have standby voltage but no LED voltage anywhere in the TV.

When I checked I noticed the Power On button on the back of the TV was mashed down, and now one side has broken off, All I can think to do is take that button off all-together and use a pencil eraser if I ever need it.

One last thing, The TV was acting strangely for months. I would turn it on but it would not light up. So I would turn it off and on again, and it would work.

Does anyone have any input on what I could or should do? Does this sound like a power supply board issue to you?

This is my power board:

https://www.tvpartshome.com/wp-conte...9/01/57-23.jpg