Vizio VF551XVT - amber logo lights but nothing else

[Jmsmbry]

The subject vizio set was working fine. Them the remote stopped working so I unplugged tv and pressed power button for 15 seconds as described by manufacturer to help in resetting the remote. After plugging tv back in, not only did remote still not work, the tv would not power on either. When I plug it in I hear a click and the amber logo lights but when I press power button, the vizio logo does not turn white like normal, no additional click is heard and no sound or picture is produced. See attached photos of all the boards. I also have checked various voltage regulators on the main board and here are the results:

U3
L474>Line 1
G1084>Line 2
Pin 1=2.02
Pin 2=3.26
Pin 3=5.08

U4
1117
Pin 1=0
Pin 2=1.25
Pin 3=3.26

U5
G1084
Pin 1=2.03
Pin 2=3.28
Pin 3=5.08

U6
1117
Pin 1=6.89
Pin 2=8.14
Pin 3=11.86

U7
1117
Pin 1=2.04
Pin 2=3.28
Pin 3=5.09

U8
7805ct>line 1
Rad9496>line2
Pin 1=11.87
Pin 2=0
Pin 3=5.0

U9
G1084
Pin 1=.55
Pin 2=1.80
Pin 3=3.27

U45
1117
Pin 1=2.0
Pin 2=3.24
Pin 3=5.09

From what I can, all these regulators look good.
Also I read 5 volts on the stand by pins on power supply board and also get the 18 and 24 volt readings as well.
Any thoughts on where else to check?

[Jmsmbry]

Re: Vizio VF551XVT - amber logo lights but nothing else

The subject vizio set was working fine. Them the remote stopped working so I unplugged tv and pressed power button for 15 seconds as described by manufacturer to help in resetting the remote. After plugging tv back in, not only did remote still not work, the tv would not power on either. When I plug it in I hear a click and the amber logo lights but when I press power button, the vizio logo does not turn white like normal, no additional click is heard and no sound or picture is produced. See attached photos of all the boards. I also have checked various voltage regulators on the main board and here are the results:

U3
L474>Line 1
G1084>Line 2
Pin 1=2.02
Pin 2=3.26
Pin 3=5.08

U4
1117
Pin 1=0
Pin 2=1.25
Pin 3=3.26

U5
G1084
Pin 1=2.03
Pin 2=3.28
Pin 3=5.08

U6
1117
Pin 1=6.89
Pin 2=8.14
Pin 3=11.86

U7
1117
Pin 1=2.04
Pin 2=3.28
Pin 3=5.09

U8
7805ct>line 1
Rad9496>line2
Pin 1=11.87
Pin 2=0
Pin 3=5.0

U9
G1084
Pin 1=.55
Pin 2=1.80
Pin 3=3.27

U45
1117
Pin 1=2.0
Pin 2=3.24
Pin 3=5.09

From what I can, all these regulators look good.
Also I read 5 volts on the stand by pins on power supply board and also get the 18 and 24 volt readings as well.
Any thoughts on where else to check?

Any help would appreciated

[budm]

Re: Vizio VF551XVT - amber logo lights but nothing else

The connector on the power supply board that goes to the main board, we need the pin name follows by the dcv reading so we can see what are missing.

[Jmsmbry]

Re: Vizio VF551XVT - amber logo lights but nothing else

Connector has the following pins and voltages:
PSON 3.12v
12v. 11.89
12v. 11.89
12v. 11.89
SGND. 0
SGND. 0
SGND. 0
SGND. 0
SGND. 0
5vsb. 5.17
5vsb. 5.17
5vsb. 5.17
A. 0
B. 0
C. 0

[budm]

Re: Vizio VF551XVT - amber logo lights but nothing else

At this point, it does look like the main board problem, it is only sending out the PS-ON but no bl-on or dimming control signals.
The Vreg Voltages also look OK.
Do you get the 24vdc and 18vdc at the other connectors?

[Jmsmbry]

Re: Vizio VF551XVT - amber logo lights but nothing else

So I should have voltages on which pins....the SGND OR A,b or C. If so how much?

[Jmsmbry]

Re: Vizio VF551XVT - amber logo lights but nothing else

Also what should I check on main board since voltage regulators are ok?

[budm]

Re: Vizio VF551XVT - amber logo lights but nothing else

So I should have voltages on which pins....the SGND OR A,b or C. If so how much?

The other connectors with the 24VDC label, and the 18VDC label, you need to see if you have them or not.
SGND is ground.
The 'A', 'B', and 'C' are the command signal pins for controlling the backjlights circuit board, they are around 3VDC TYP., most of the time they only use A and B only.
I cannot tell you where the problem is on the main board with out diagram, it is complex board.
You may want to contact shopjimmy to see what they suggest, it can also be that something is locking out the main board.

[Jmsmbry]

Re: Vizio VF551XVT - amber logo lights but nothing else

I do have 18v and 24v at the appropriate other pins. Not getting any voltage on any of the A orB pins

[Jmsmbry]

Re: Vizio VF551XVT - amber logo lights but nothing else

Do you know how to identify the eeprom?

[ecking767]

Re: Vizio VF551XVT - amber logo lights but nothing else

the EEPROM is located near the label with bar code and the small label with TV model number written on it.

I have troubleshooted this model Vizio a lot and when all voltage regulator are active like your, this tell me the CPU isn't functioning. most likely the CPU is fried. you can try replacing the EEPROM if you like. but don't get your hope up!!

In standby mode your +12 shouldn't be active and I know U6 shouldn't be active.

[Jmsmbry]

Re: Vizio VF551XVT - amber logo lights but nothing else

I guess if CPU is fried, I just need a new board?

[Jmsmbry]

Re: Vizio VF551XVT - amber logo lights but nothing else

This board seems hard to find. Any good sources out there?

[Nick's Tvs]

Re: Vizio VF551XVT - amber logo lights but nothing else

EEPROM rarely fails on this board. Remove the silver heat sink from the board to reveal the BGA chip below. Then freeze it with freeze spray or upside down can of air. Then turn the TV on. You may see the TV turn on or at least start to initialize instead of not responding.

[Jmsmbry]

Re: Vizio VF551XVT - amber logo lights but nothing else

Thanks for your reply (nicks tv). If it turns on after freezing, does that verify a bad BGA chip?
Why is the replacement board so hard,if not impossible, to find. You hate to throw away an entire tv because of one part!

[Nick's Tvs]

Re: Vizio VF551XVT - amber logo lights but nothing else

Sorry for that late reply but yes indeed that would confirm that it is the failure.

[nomoresonys]

Re: Vizio VF551XVT - amber logo lights but nothing else

one main board on ebay 113 or best offer.