Vizio D55un-E1 No picture or Backlights

[blake.s]

I have a Vizio D55un-E1 that has both no backlights or picture to the screen. I try to flash a light to the screen and cannot see any faint picture. When the tv is plugged in and powered on the led light will show for a couple seconds and then slowly fade away. Pictures are posted below.

[blake.s]

Re: Vizio D55un-E1 No picture or Backlights

I get 34 volts testing out of VLED pins and when testing the pins from power supply i get voltages that are correct towards the reference key.

[R_J]

Re: Vizio D55un-E1 No picture or Backlights

I get 34 volts testing out of VLED pins and when testing the pins from power supply i get voltages that are correct towards the reference key.

Monitor the VLED voltage when you first turn the tv on, Does it come up to a higher voltage then drop down to 34 volts?
What is the voltage on 15- BL_O/F and 16 - DIM

[blake.s]

Re: Vizio D55un-E1 No picture or Backlights

When the tv is first turned on it will go to 55v/56v and then drop to 34v. When powered on and off again it will just go to 34v. The only time i can get it at 55v ish is when i unplug for a couple seconds and plug the tv back in.

The voltage on 15- BL_O/F and 16 - DIM is at 4.8v.

[R_J]

Re: Vizio D55un-E1 No picture or Backlights

If the voltage gets to 55~65v then drops , this usually indicates an open led string. The led circuit monitors the led current and will error if it is to high or in this case likely 0 current.
If you look at the back of the board and CN9101, pins 15&16 may not be used

[blake.s]

Re: Vizio D55un-E1 No picture or Backlights

Which means the led strips are causing it to function that way? That was my original thought, just thought i would verify my thinking.

[R_J]

Re: Vizio D55un-E1 No picture or Backlights

Which means the led strips are causing it to function that way? That was my original thought, just thought i would verify my thinking.

That's what it looks like. an led tester could confirm it without opening the panel

[blake.s]

Re: Vizio D55un-E1 No picture or Backlights

I have an led tester. How is that done without opening the panel?

[R_J]

Re: Vizio D55un-E1 No picture or Backlights

Unplug the connector from the power supply and use the + of the tester on one of the brown wires and the - on the black wires. If you probe at the panel, I suspect all the browns are connected together at the panel, so probe at the panel end. It might not be a bad led but a poor connection in that panel plug