Re: Another Vizio SV421XVT that won't power up

So I ended up taking the output of regulator U5 and running it through a 330 ohm resistor to the wire I pulled for the INV ON/OFF signal going back to the power supply. About 95% of the TV works, there are only 2 things that don't:

1) The Power/Standby indicator always shows amber like it's in standby. No big deal.
2) The 3 HDMI ports on the back of the TV are dead. However the 4th HDMI port on the side works great.

The Tuner, all the AV and component jacks work just fine and all of the functionality...

Re: Another Vizio SV421XVT that won't power up

Well I screwed up, I was looking at U5 instead of Q5

At the output pin of the regulators
_____off____on
Q1 = 5.00v 0.00v
Q2 = 0.00v 0.70v
[COLOR="Red"]U5 = 0.00v 3.30v[/COLOR]
Q7 = 0.67v 0.72v after about 3 seconds it goes to 0.03v
Q8 = 0.00v 3.21v

I pulled the board and then took the one cap off and took a lot of pictures so I could accurately trace what goes where. I even metered out from this via pass through to all the transistors and could not find...

Re: Another Vizio SV421XVT that won't power up

Been trying to work on the TV, but it's been sporadically.
The fuses are all OK.

I looked at this other thread which was basically the same problem as me and did some of the same troubleshooting.
[url]https://www.badcaps.net/forum/showthread.php?t=34258&highlight=sv421xvt&page=3[/url]

Leaving the Main Board (pin1)
INV ON/OFF = 1.07v (off) - 1.19v (on)

At the output pin of the regulators
_____off____on
Q1 = 5.00v 0.00v
Q2 = 0.00v 0.70v
...

I have a 42" Visio SVT421XVT that suddenly won't power up a few months ago. The orange logo is on the front is lit and never changes to white.

I've used an Ohm meter, Capacitance meter and ESR meter to check all the can type cap's. I have replaced a number of cap's that where bad or questionable on both the power inverter and main board. Still no difference. From what I'm seeing, I believe the problem is on the main board.

These are the chip part numbers and the current voltage readings. All these readings are with the power on/off button being held on.
...

Re: New Members - please post your introductions here

Hi Everyone,
I got my electronics training back in the early 70's. Worked on computers and other large electronic equipment for 20 years. Then I moved over to the software side for the next 19. I occasionally tinker around with electronics and repair stuff. I'm trying to repair my LCD TV and am making no progress. Found this site while searching the net.