vizio xvt553sv no dc power

[Cwolfe24]

I have a vizio xvt553sv tv that won't power up. I've taken the back off and I have 120 volts on the ac side. I can't find any dc voltage on the other side. Can someone tell me how to correctly check this. Thank you

[budm]

Re: vizio xvt553sv no dc power

You can start with this:
https://www.badcaps.net/forum/showthread.php?t=39740

[Cwolfe24]

Re: vizio xvt553sv no dc power

I believe I have attached a picture of the board, I will read all the material you suggested thank you

[budm]

Re: vizio xvt553sv no dc power

OK, what DCV do you have when measure between the two legs of the main filter cap C800A? Be real careful since you will be working in the HOT Deadly side of the circuit.
http://www.shopjimmy.com/vizio-0500-...pply-unit.htm#

There are two fusible resistors R922, R601 that need to be verified that they are <1 Ohm.

DELTA DPS-278AP

[Cwolfe24]

Re: vizio xvt553sv no dc power

I just checked c800a filter cap with a dc voltage of 170 the resistors r922 and r601 have o resistance, but The only voltage I can find on the secondary side of the board is the c 951A ,B, and C capasitors showing 5 volts when turned on and 3 volts when turned off

[Cwolfe24]

Re: vizio xvt553sv no dc power

I purchased a new power board but the screen is still black. Can someone please give me some advise on where to go from here.

[budm]

Re: vizio xvt553sv no dc power

You need to find out if you do have the control signals from the main board to turn on the main power supply and and the backlights circuit.
So do have close to 400VDC between the two legs of the main filter cap?

[Cwolfe24]

Re: vizio xvt553sv no dc power

Thanks for responding. I have 169 volts dc across the main filter cap.

[budm]

Re: vizio xvt553sv no dc power

Thanks for responding. I have 169 volts dc across the main filter cap.

OK, no boosted Voltage, then we need to find out first if you have 5VDC at connector CN202 PIN 1~3 (5VSB) or not, if you do, then hit the power switch then see if you have >2VDC at CN202 pin 11 (REMOTE ON/OFF) or not.

[Cwolfe24]

Re: vizio xvt553sv no dc power

Ok, I have 5 VDC at cn 202 pin1~3 and when I hit the power switch I have 0VDC at cn202 pin11

[Cwolfe24]

Re: vizio xvt553sv no dc power

I hit that smiley thing by mistake

[budm]

Re: vizio xvt553sv no dc power

OK, the new power supply is supplying the 5VDC to run the main board but the main board is not sending out the ON command signal to turn on the rest of the power supply.
So troubleshooting the main board will be next.
BTW, what is the history of this TV?

[budm]

Re: vizio xvt553sv no dc power

Does this main board have the same P/N as your board? Very expensive board!
http://www.shopjimmy.com/catalogsear...vizio+xvt553sv
You may want to try disconnecting the WIFI module and the Bluetooth module, T-CON to see what happen.
BTW, what is the history of this TV?

[Cwolfe24]

Re: vizio xvt553sv no dc power

The tv was a friend of mine's, he said it just quit turning on so he bought a new one. The p/n is the same for both the new and the original boards. I don't know which components are what. Starting from the bottom of the tv there is a board to the left of the power board, a board center top and a board on the right side. I don't know what btw means I hope you can walk me through this. I'm leaving for work I will check back this afternoon. Thanks

[vinceroger69]

Re: vizio xvt553sv no dc power

can you upload clear pictures one showing the whole back of the tv with all boards attached then one picture of each board then we can try to advise what to test next.

[Cwolfe24]

Re: vizio xvt553sv no dc power

Here it is

[Cwolfe24]

Re: vizio xvt553sv no dc power

I have the pictures I don't know how to send them

[Cwolfe24]

Re: vizio xvt553sv no dc power

I'm trying one at a time

[Cwolfe24]

Re: vizio xvt553sv no dc power

One more

[Cwolfe24]

Re: vizio xvt553sv no dc power

Sorry I've never done this