Vizio VO42L FHDTV10A Won't power on

[hawkbug]

I have read all the other posts on this forum regarding this model, the Vizio VO42L FHDTV10A. Every pic I have seen where somebody has fixed it is of another power supply that I don't have in my set. I took some pics with my cell and attached. I hope they are helpful. If not, I can try to take some more - but all I have is a cell phone.

The TV worked fine for the past 4 years, until today. It was on and the kids were watching cartoons. Then all of the sudden, there was a pop and everything went dark. The vizio light on the front does not come on anymore when plugged in. In my very limited experience, when I hear a bang and smell fire, it's normally a popped cap. Yet, I have looked all over the power supply, inverter, and main board - and I can't find any visible signs of a popped cap.

Can anybody with more experience see anything useful from my attached pics?

[ryan74]

Re: Vizio VO42L FHDTV10A Won't power on

I suggest start by checking voltages on power supply to make sure it is a power supply problem. It looks like the voltage is printed on the board.

[budm]

Re: Vizio VO42L FHDTV10A Won't power on

Check the Mian AC fuse and the voltage at the 5VSTBY pin for 5V, this voltage should be there the minute you plug the TV into the AC outlet.
More likely the power supply has died.
New board is about $50.
http://www.shopjimmy.com/vizio-0500-...wer-supply.htm

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

Thanks for the info. I'll try to find that location on the board and test it without killing myself

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

Huh, so the main fuse on the power supply is definitely blown. I put my tester on it, and it doesn't allow current through at all. So, where would I find a replacement? And aside from a power surge or something, is there anything on the TV itself that could have caused this?

[budm]

Re: Vizio VO42L FHDTV10A Won't power on

If the main fuse is blown, then you may have shorted Bridge, rectifier, MOSFETS, etc.
What you can do is to use 75W lamp in the socket with two wires coming off, then connect each wire to the each end of the fuse (you are basically putting the lamp in place of the fuse), then plug the TV into the outlet, if the lamp stays on brightly lit, then you have real bad shorted circuits.

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

Ok, thanks for the tip. I'll try that this evening with some gator clips and a bulb. Now when you say mosfets, I assume those are the little black chips on the power supply?

[budm]

Re: Vizio VO42L FHDTV10A Won't power on

Big 3-leg devices mounted on the heatsinks (some are Diodes also).

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

Well, due to a lack of time, I just purchased a new power supply for it off of Ebay. I purchased the power supply I have seen in all the other pictures for my model of TV on these forums. While yes, the power supply does in fact work, it emits a horrible high pitched noise when plugged in. Is that a bad capacitor or part on the board making that sound? Should I send the board back as defective?

[tom66]

Re: Vizio VO42L FHDTV10A Won't power on

Depending on where the whining is coming from it can either indicate a bad capacitor or no fault at all. If it is the "no fault" option, it could be dried up varnish/epoxy on an inductor or transformer, or a cracked ferrite core. Perhaps a swap would be the best option.

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

Being the n00b that I am, I can say it's coming from the left side of the board - under or near the metal shielding with the capacitors. There are 3 white connectors on that side of the board, and from what I can tell, it's coming from the caps under the metal or the 2 bigger items in the middle of the board. The noise starts slowly - like something switching on and off and it gets faster. Eventually ending up in a higher pitched constant noise. When the TV is powered on, it goes away.

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

Attaching 2 pics of the new board. The second pic shows some what looks like grey paint on this one part, looks like a copper spring. Could that make that noise?

[tom66]

Re: Vizio VO42L FHDTV10A Won't power on

Those are common sources of whining noises -- it's called coil whine. Sometimes a dab of epoxy or glue can sort it.

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

Cool, thanks. I just try to glue the copper part? Would elmers super glue work?

[tom66]

Re: Vizio VO42L FHDTV10A Won't power on

Super glue may work. I've used epoxy successfully in the past, so I'd recommend it myself.

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

Well, upon further inspection, it appears to be coming from the big yellow block in the middle of the board. If my ears can be trusted that is.

[tom66]

Re: Vizio VO42L FHDTV10A Won't power on

That may be a fractured ferrite core. Try gently squeezing the component to see if it stops... don't touch any metal parts!

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

I tried squeezing it, and it's a solid block. I can't budge it. I'm almost positive that's it. There is writing and numbers on the side of the thing. I'm thinking I should just send the power supply back and get a new one from the ebay seller.

[tom66]

Re: Vizio VO42L FHDTV10A Won't power on

I would recommend that.

Out of curiosity, how old are you (approximately)?

As you get older you can't hear higher frequencies so well.

It could be normal for it to make that noise, but putting the case on and sitting 10ft back makes it mostly inaudible.

[hawkbug]

Re: Vizio VO42L FHDTV10A Won't power on

I'm 34. I have weird hearing. I had my hearing for a job tested once when I was 19, and they told me my hearing with low frequencies was that of an 80 year old man, but my hearing for high frequencies was right on the money. Not sure how that happened