Vizio XVT3D650SV - Help

[newpey]

Re: Vizio XVT3D650SV - Help

I will order a main board then! Thanks for all the help guys!

[bammbammfran]

Re: Vizio XVT3D650SV - Help

well, the controller chip (whichever one it might be) is getting 5 volts and turning it to 3.3 and trying to turn on, but isn't
It may be the chip under the one heatsink ? or could be somewhere else and trring to figure it out could be rough.
you would first have to try to figure out where the power button 3.3 volts is coming from to have any clue where to start. even if you find that chip, it could be something else stopping it !

[newpey]

Re: Vizio XVT3D650SV - Help

Hah figures!

Both are the same. I just just tested pins 1-16 on main board and power board. Pushing the button doesnt change anything

[bammbammfran]

Re: Vizio XVT3D650SV - Help

well. I was hoping for an easy fix like a bad button, BUT, NOT !

do both power supplies give the same results voltage wise?
Did you recheck pin 13 and pin 14 & 16 to see if they show any signs of a voltage rise wile you push the power button (I think you checked 13 but not sure if you check 14 or 16)

[newpey]

Re: Vizio XVT3D650SV - Help

I have 1 pin that has power 3.3v on both sides of ribbon. When power button is pushed it drops off to 0 on both sides

[bammbammfran]

Re: Vizio XVT3D650SV - Help

OK
I figure it might be multifunction
check for voltage at the 8 pin plug at the main board side (I think it is a J7 plug)
Then recheck the voltages at the power button end to make sure they are the same.

If you find voltage on a pin
Hold the tester in place so that you can see if the voltage drops when you push the power button. If you have several pins with voltage, keep check them to see if one drops

[newpey]

Re: Vizio XVT3D650SV - Help

The group of picutes "Round 2" IMG_20140703_133842.jpg is the power switch board. The power switch pushing in to turn on/off. If also rotates to interact with the menus

[bammbammfran]

Re: Vizio XVT3D650SV - Help

On post 2 with your first set of pictures: Is that the power button shown on the second to last picture ? is it the bottom one in the picture with the 8 pin connector ?
If it is, does it rotate or push to turn on and off and does it normally do any other functions ?

[newpey]

Re: Vizio XVT3D650SV - Help

OK, so the main board is not sending the PS_ON signal, so main board is the problem right now.

Are you saying I should just order a main board from vizio? I would like to try to find the root cause as I can solder. A new main board will cost me around $150 (which may be ok but I need to fully know it is a main board issue cause I'm already -$100 on a new power board that didnt solve it).

I would scrape the tv but I spent a lot on it and barely had the money at the time to buy it and dont have the money now to replace it

[budm]

Re: Vizio XVT3D650SV - Help

OK, so the main board is not sending the PS_ON signal, so main board is the problem right now.

[newpey]

Re: Vizio XVT3D650SV - Help

OK so no matter which combination (plug in, pushing power button or plug disconnected) it always stays at 0

[bammbammfran]

Re: Vizio XVT3D650SV - Help

No change on pin 13 when pushing the power button with cn202 connected or disconnected

Now that we can get a good voltage:
so, is pin 13 showing voltage even if the main board is disconnected from the plug ? and is it still showing 5 volts ?
OR
Is it showing no voltages ?

[newpey]

Re: Vizio XVT3D650SV - Help

The TV *normally* goes through a boot up stage when you first plug it in. During that time the vizio logo lights up orange then proceeds to flash orange and white. Once it is complete the logo go back to orange and the power button becomes enabled and you can turn on the TV.

I am guessing the power button will not change the voltage as the tv is not "booted up".
I am not sure I just know that it used to take 1-2 minutes before the power button worked

[newpey]

Re: Vizio XVT3D650SV - Help

No change on pin 13 when pushing the power button with cn202 connected or disconnected

[bammbammfran]

Re: Vizio XVT3D650SV - Help

ok
That is better
Now you can recheck pin 13 that budm wanted to see the value of when powered on and off and connected to the main board
also check it at the power supply with wires to cn202 disconnected

[newpey]

Re: Vizio XVT3D650SV - Help

OK the multimeter I had was defiantly NOT matching the new one. Now maybe we can actually get somewhere! Sorry about that guys!!

Here are the readings:

Power board plug
1 5.1-5.3
2 5.1-5.3
3 5.1-5.3
4 5.1-5.3
5 0
6 0
7 0
8 0
9 0
10 0
11 0
12 0
13 0
14 0
15 0
16 0

caps on power board:
C951A 5.22
C951B 5.22
C951C 5.22

C800A 77.7
C800B 77.7
C800C 77.7

-----

Main board

Fuses
F3 5.1
F1 0

Voltage Regulators
U8
in 0
out 0
gnd 0
tab 0

U38
in 0
out 0
gnd 0
tab 0

[newpey]

Re: Vizio XVT3D650SV - Help

I think we are are doing wild goose chase with all these wrong readings. The only correct reading is the one on the main filter cap that shows around 160VDC.

I am going to get a new tester this morning. Maybe it is the issue. I will post all new readings one I get it.

[budm]

Re: Vizio XVT3D650SV - Help

I think we are are doing wild goose chase with all these wrong readings. The only correct reading is the one on the main filter cap that shows around 160VDC.

[bammbammfran]

Re: Vizio XVT3D650SV - Help

The probe wires are soldered on to the meter. Battery is fine as well. If I am reading the pins correctly then they go like this..

back side
16, 14, 12, 10, 8, 6, 4, 2

front of plug that is facing me
15, 13, 11, 9, 7, 5, 3, 1

JUST TO MAKE SURE
See the picture
ALSO, please check these with the plug from the main board unplugged
USE GREEN marked pins for black probe of the tester

[budm]

Re: Vizio XVT3D650SV - Help

Can you show us the meter?