Short to ground, or low inverter voltage?

[NeedsMoreFlux]

Im working on a toshiba(samsung) board.

I think a cap is shorted to ground.

But the "inverter" wire has 3 volts coming out of it. I assume this is just the on signal. Since it is just one wire. while the 24v/ground have 4-5 wires in common(connected to each other on the inverter board.

I'm going to upload some photos.

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

I think that worked.

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

The important one is blurry, this should be clearer.

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

Oh well, its clear enough to see the wire that I am talking about. the longest name printed on there says inverter.

Am I supposed to only get 3 volts?

This is on a LCD with CCL/CFL(?)

[budm]

Re: Short to ground, or low inverter voltage?

Still way too blur to see the prints.
Makes and Model of the TV????

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

toshiba 40RV525R

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

Ka-CHOW!

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

After replacing the blown fuse I have 0 volts!

If I unplug that wire I have 24 volts...

Perhaps I should run 24 volts through it and see what smokes

Oh and the connector flips upside down on the receiving end-inverter board.

[budm]

Re: Short to ground, or low inverter voltage?

Ka-CHOW!

https://www.badcaps.net/forum/attach...3&d=1510870051
Inverter pin = BL-ON command from the main board
3V = Backlights ON, <1V = Backlights OFF

[budm]

Re: Short to ground, or low inverter voltage?

After replacing the blown fuse I have 0 volts!

If I unplug that wire I have 24 volts...

Perhaps I should run 24 volts through it and see what smokes

Oh and the connector flips upside down on the receiving end-inverter board.

Which blown fuse? On the power supply board? On the Inverter board?

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

this is the fuse, I had 2x3amp fuses.

This is on the inverter board.

[budm]

Re: Short to ground, or low inverter voltage?

You need to check all the power MOSFET's that drive the primary side of the Inverter transformer to see if any one of them has very low resistance between the S and D pins of the MOSFET's.
Also look real close at those Inverter transformers to see if any one of them has sign of over heating or not, look at both dies of the board to see if there are any brown spots where the transformers are.

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

I think I found the short!!!!!

A 6 legged smd mosfet(?)

I will take pictures and when I finish testing I will post the results!

I need to buy a q600 microscope so I can get better pictures!

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

I gotta find some of these 6 legged ICs. I've been looking and haven't found any yet.

4614 BV9L1F

I'll try to get some good pictures.

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

And if anyone can identify that brand my thanks go out to you!

looks like it's "AO" brand(?)

But I'm not finding anything with the same second number.

Perhaps the second number is just the manufacturing date(?).

[vinceroger69]

Re: Short to ground, or low inverter voltage?

maybe this


I think the numbers on the second line is a date code etc

[diif]

Re: Short to ground, or low inverter voltage?

Alpha and Omega Semiconductors.
AO4614 is not hard to find.

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

Agreed, diif. But what about the second number? Is it just a manufacturers date code?

[NeedsMoreFlux]

Re: Short to ground, or low inverter voltage?

Thank you vince and diif!!!

I will order these, and wait about 2 months for them to show up from china!

Yay!

(I'm gonna look through my box of spares and see if have any.

[diif]

Re: Short to ground, or low inverter voltage?

Thank you vince and diif!!!

I will order these, and wait about 2 months for them to show up from china!

Yay!

(I'm gonna look through my box of spares and see if have any.

Available from Digikey.