Bad transformer

[splitcrete]

Hi everyone : I need some help with my proscan 32la30q
I was checking the power board and found the f1 fuse blown.So I started looking for a reason it was bad I have a bad primary coil in one of the transformers. My problem is I cant get one any where . Its a (PULSE ELECTRONICS) number PF0082 I would be thankfull for any help.
Thanks,Splitcrete

[budm]

Re: Bad transformer

What resistance do you get? Primary side rarely fail, its DC resistance will typical be less than 1 Ohm. I doubt that you have bad transformer.
Did you chekc the rectifers, MOSFET'S, etc?
Any picutres of the boards?

[splitcrete]

Re: Bad transformer

I have no reading at all and the transformer is off the board.
F1 only blows with transformer on the board.

[splitcrete]

Re: Bad transformer

The wires on the pri.side are burned off.

[tom66]

Re: Bad transformer

The transformer is just a part of the supply. Something in line with it is more than likely failed; probably a shorted MOSFET, which drives the transformer.

[splitcrete]

Re: Bad transformer

I checked all fets and the gates work on all of them.Pain in the butt with a 9v battery.
This set had a lightning surge and the power strip even burned out.So much for bargen power strips.

[tom66]

Re: Bad transformer

The only way to be sure is to test it with a ring tester, but I doubt you have one. Another possibility is the controller IC is damaged and the output is stuck permanently on, which will blow the fuse.

[splitcrete]

Re: Bad transformer

No I dont have a ring tester. I was looking for a board but no luck.Mabey I can find a generic one somewhere.

[tom66]

Re: Bad transformer

I would first consider the controller IC. How about a picture of the board so we can locate the components on it.

[selldoor]

Re: Bad transformer

Tom - did you see post4

Splitcrete - are you saying there are NO primary wires

[tom66]

Re: Bad transformer

Could be varnish, would need a pic.

[budm]

Re: Bad transformer

Cannot do much until we see good clear pictures.

[splitcrete]

Re: Bad transformer

I'll try to post pic.

[splitcrete]

Re: Bad transformer

If more pics are needed I can post later today.

[splitcrete]

Re: Bad transformer

I have more pics.And yes I'm changing all the caps most were bad.

[retiredcaps]

Re: Bad transformer

This may not be the case, but I saw one youtube video sometime last year where there was a thermal fuse inside the secondary windings of the transformer. Yes, I realize the OP is talking about the primary side in this thread.

See

https://www.badcaps.net/forum/showthread.php?t=18051

[tom66]

Re: Bad transformer

Looks like varnish to me, nothing to worry about.

What else is in series with the transformer? Other than the MOSFET...

[budm]

Re: Bad transformer

That is PFC choke which is in series with the MOSFET to ground. You can see the MOSFET and the PFC Diode mounted on the same heatsink as the Main bridge rectifier. It will have only two windings, one is for the PFC booster, another one is for Phase detection (not all PFC uses Phase detection through the winding, so it may have only one winding)).

[selldoor]

Re: Bad transformer

The wires on the pri.side are burned off.

What exactly did you mean by this?

How about a clear infocus picture of the bottom of the transformer.
Try in better light.

[budm]

Re: Bad transformer

Also circle the one with open winding.
Also pictures of the back side of the board.