Vizio VF550XVT1A Constant Black Screen.

[seananamous]

I have a Vizio VF550XVT1A.

Problem:Constant Black Screen

What works: Vizio Logo under screen.

What I Tried: flashlight on the screen to see the menu but no success, also no backlights pertruding from the holes are visable.

As I've seen others post about this Tv, it could be the main board that is the issue. How am I able to test it? Attached are pictures, I have a multimeter if you could show me where that would be great!

I did also check out the T-Con Board - pic attached, there is a little discoloration as you will be able to see and the ribbon has some "stuff" on it..

[ReeceyBurger123]

Re: Vizio VF550XVT1A Constant Black Screen.

Tcon is fine by the sounds of it. Have you a multimeter and know how to test dc voltages ?

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

Tcon is fine by the sounds of it. Have you a multimeter and know how to test dc voltages ?

Thanks for the prompt reply,
I do have a multimeter and have somewhat an understanding on how to test.
What locations should I use it on?
I can also get a better picture of the main board if needed.

[dick_barton]

Re: Vizio VF550XVT1A Constant Black Screen.

Do you have sound and does the set appear to respond to the remote control.

[ReeceyBurger123]

Re: Vizio VF550XVT1A Constant Black Screen.

You see the two inverters. There is a master inverter (mounted to the left side of the screen) and a slave inverter (mounted to right side slightly under mb case) study the connectors.

Are the pins labelled with voltages ? Normally there is 24v, Blon whoch is 3.3v and dimming normally about 1.4v.

You should hook your meter up and see if you have the, voltages present to the inverter first.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

I see the master inverter you are talking about although I dont see any voltages. I dont want to shortcut anything as that may ruin the chip...
Want me to supply a picture of the master?

And dick_barton, there is no sound.

[ReeceyBurger123]

Re: Vizio VF550XVT1A Constant Black Screen.

So you dont have the 24v going to inverter ? Black probe on chassis, red probe to test the pins and meter set to 600v dc range.

Also where do I recognise your user name from lol ?

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

Well, I'm everywhere...

But attached is an image of the inverter. I do not see 24v written anywhere or if you catch it then Im blind.

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

https://www.badcaps.net/forum/attach...9&d=1465778517
Do you see the chart to the left of the white connector connector that goes to the power supply?
Give the list as to what they are.
You can also check the for 24VDC on BOTH end of the white fuse with ref to the chassis.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

1-VIN
2-VIN
3-VIN
4-VIN
5-VIN
6-GND
7-GND
8-GND
9-GND
10-GND
11-VBR-A
12-On/Off
13-EXTBR_B
14-Status

I'm trying to read this through an image of mine. Is this what you mean?

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

Vin = 24V.
So report the DCV readings of all those Pins.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

Ok just an update, it's not the main board that is the issue. Just swapped board and had the same problem. As for taking the readings for the pins can you explain how exactly to do it? black and red on which pins and what to keep it on as i move the black to the next pin. I tried it and heard a pop... probably not good lol

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

Turn the TV on, black probe on the chassis and red probe on each one of those pin and then report the DCV reading for each pin with the pin number and pin names for each pin.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

Turn the TV on, black probe on the chassis and red probe on each one of those pin and then report the DCV reading for each pin with the pin number and pin names for each pin.

Thanks,
Ok from the start-

Vin-
1: 23.8
2: 23.8
3: 23.8
4: 23.8
5: 23.8

Gnd-
6: 0
7: 0
8: 0
9: 0
10: 0

VBR-A
11: 1.3

On/Off:
12: 4.9

Extvbr-B
13: 0

Status:
14: 0

Anything you see wrong?
Multimeter is set to : 200v

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

The inverter is getting the 24, the BL-ON (ON/OFF pin 12), the Analog dimming (VBR-A) so the problem is some where in the inverter board.
BTW, are you getting 24VDc at BOTH ends of the WHITE fuse with ref to the chassis GND?

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

If by what you mean the white wire which is gnd, both ends are "0"

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

https://www.badcaps.net/forum/attach...9&d=1465778517
Fuse F1 with white body with silver ends to the right of the connector.

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

https://www.badcaps.net/forum/attach...9&d=1465778517
Fuse F1 with white body with silver ends to the right of the connector.

I dont quite know where f1 is, can you explain more in depth please?

Edit:
Ok I took a look in depth at the chip and see f1. You want me to connect the white wire to that exact portion? - see image
Thanks for your help so far!

[budm]

Re: Vizio VF550XVT1A Constant Black Screen.

Did you look at the picture and the location I indicated?

[seananamous]

Re: Vizio VF550XVT1A Constant Black Screen.

Yes I see the inverter you're referring to. See my edit in the previous post and attached image.