Re: Vizio E7-E3 Black Screen
Hi Bud, can you please take a look at my last post and comment please?
Thanks,
Bob...
BobbyG58
Member
Last Activity: 11-03-2019, 09:58 PM
Joined: 09-11-2018
Location: Owatonna
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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...Last edited by BobbyG58; 04-04-2019, 07:58 PM.Leave a comment:
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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....Leave a comment:
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Re: Vizio E7-E3 Black Screen
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....Leave a comment:
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Re: Vizio E7-E3 Black Screen
Thanks Budm, I use SJ from time to time. I see they have a full board set for a good price. I may just go that route.
Can you answer one more question please?
I am still confused about the voltage on the black leads coming back from the strips.
Not fully understanding why there is voltage going in but not coming back.
In my simple mind, I am thinking about water flow with a single hose feeding both strips and a hose on each strip coming back with equal water flow from each...Leave a comment:
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Re: Vizio E7-E3 Black Screen
I was just watching a YT video on PSB. In that video, the two capacitors that I checked on my board you mentioned a PFC and in the video the guy had a similar situation where Budm told him that his board had no PFC and that his low voltage of 360v would be normal.
I am wondering how I tell if the board has a PFC and if my board might be similar to the one in the YT video?
My thinking right now is if my 297v is too low for this board, then I should replace the PSB first and eliminate any power supply issues and...Last edited by BobbyG58; 12-20-2018, 11:05 AM.Leave a comment:
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Re: Vizio E7-E3 Black Screen
Wow, I searched right before you sent this and only found $20-$60, thanks.
Back to the PSB low voltage caps, should I think about a new PSB also?...Leave a comment:
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Re: Vizio E7-E3 Black Screen
I counted around 30. Any idea where on the board I would be looking?...Leave a comment:
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Re: Vizio E7-E3 Black Screen
I looked at the pdf, Although I can recognize many components in a schematic, I won't even pretend what it is telling me about what it is doing and about no return voltage on the black return wires. Could a bad U400 cause this issue?...Leave a comment:
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Re: Vizio E7-E3 Black Screen
Ok, I unplugged the T-con from the panel, no change. I reconnected the panel and disconnected the VSNS cable and no change.
In regard to probing the black wires, I should find 2 corresponding black wires to 1 red wire?
The U400 is an AS3820
I also went back and looked at the youtube video. It appears that the output from the main board plugs directly into each strip. i.e. no board in between the MB and the LED strips....Leave a comment:
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Re: Vizio E7-E3 Black Screen
I understand, However you had mentioned voltage on the black wires. In this case of 57v on the Red, should each black show half of the 57v?
Right now of course I get 0v on those. But when all is working should they read half of the 57v?
If I purchased an LED tester, could I unplug the connector from the main board and probe one red wire and just probe each black wire until I hit the correct corresponding black wire to light the strip?Last edited by BobbyG58; 12-19-2018, 11:12 AM.Leave a comment:
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Re: Vizio E7-E3 Black Screen
Do you mean the 3 silver "can"capacitors? I can check those later today if those are the ones you are thinking....Leave a comment:
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Re: Vizio E7-E3 Black Screen
Hi Bud, on your points.
1) When I looked at the E70-E3 LED replacement video on youtube, what I saw, correct me if I am wrong, was 6 rows with two strips per row.
1 Full row/ 2 strips = 18 LEDs with 9 per strip 9x2. If as you say VF = 3.1v x 18 =55.8v per row.
Maybe I am not thinking correctly. As you mentioned 1 red per row and one black per strip.
As for the black wires, I am not familiar with how an LED circuit works but if I understand correctly, there SHOULD be in this case of 57v per red, 28.5v(57v/2)...Leave a comment:
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Re: Vizio E7-E3 Black Screen
Sorry, No I don't have the panel number. Is that on the chassis somewhere?
I am thinking about the 380-400v caps PFC.
If one went bad would that take half the screen and then the second failed taking the rest of the screen?
BTW thanks to both of you for taking the time to walk me through this....Last edited by BobbyG58; 12-18-2018, 07:31 PM.Leave a comment:
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Re: Vizio E7-E3 Black Screen
The 12 strings goes with the video I watched. 2 wide and 6 rows. 3.1v x 18= 55.8v or the 57v on the LED side.
So if I understand correctly, you are leaning the same way nomoresonys is leaning. A bad power supply board/ component? If so would the symptom of half the screen black first followed later by both sides be the same result of this PSB/ component?...Last edited by BobbyG58; 12-18-2018, 07:09 PM.Leave a comment:
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Re: Vizio E7-E3 Black Screen
I have a question about the LED circuit. Why are there 2 ground/ black going from the MB to the LED circuit? What is the purpose of the 2nd GND/ Black?...Leave a comment:
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Re: Vizio E7-E3 Black Screen
I have 57v on the Red Wires and 0v on the black wires.
I did not recheck the voltage on that connector with the LEDs unplugged.
After watching a SJ video on this unit, there are 6 rows of LEDs which would coincide with the 6 Red leads and the 12 black leads. 1-Red and 2-Black for each Row....Last edited by BobbyG58; 12-18-2018, 03:01 PM.Leave a comment:
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Re: Vizio E7-E3 Black Screen
No change in voltage with LED connector unplugged from Main Board....Leave a comment:
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Re: Vizio E7-E3 Black Screen
There is only one connector going out from the PSB.
On the Main Board there is one going to LEDs, one going to the T-Con The one for standby/ menu/volume board and one for audio
and the VSNS ribbon....Leave a comment:
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Re: Vizio E7-E3 Black Screen
Do you mean unplug C201 from PSB to Main Board and check?...Leave a comment:
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