On Thursday, June 9, 2016 at 5:42:12 AM UTC-5, wrote:
Hi there
I'm repairing a variable smps based on SG3525 IC. the IC gets too hot and finally it burns away. what's the problem?

That is like way too much not enough information.

Is it used to drive a transformer directly or transistors ? If directly, what about the load on the transformer, have you checked the rectifiers on the secondary ?

You have to give some ****ing information to get help on **** like this. Does the thing, whatever it is, work but then it pops ? Or just fry out and not work ?

Get more info out here, and actually the duty cycle of the waveform it is putting out. Get a Dropbox account and use the \public directory for pics like this. When you try to use their picture thing it gets all ****ed up.

And what is the make and model of this thing ? Unless it is some homebrew custom thing...

If you are unable to supply this information you have no business trying to fix the thing. If you have changed that IC fifty times you have no business trying to fix that thing.

When I ask for help here I got voltage readings, waveforms and all kinds of tricks I did to find out this and that. Sometimes it works ad sometimes nobody knows. You come in here with a post like that most people think you are a total noob and don't know ****.

Now it is up to you to prove otherwise. We can't read your mind or your scope, and you better have one. Of each.