Replacing a 4 pin leaded inductor with a 2 pin

gkmaia said:

As a feedback for the whine. I unwired the coil. Rewired it with a good coat of varnish and put it back. It is 90% quieter now.

Click to expand...

But that sounds like you're treating the symptom rather than the fault, have you checked the electrolytics for high ESR - as you've already had one fail, the rest are probably in a similar state.

BTW, Firefox here, and the pictures just appear - no suggestion that they are hosted elsewhere.

I've added the images to the original post.

What happened to this device was a massive electrolytic leakage. It is case is really yellow so I suspect it was used for a long time under direct sun light and heat. I ended up replacing all the electrolytics around the power supply area.

Before and after replacing the electrolytics the whine was the same.

What really made a difference was the varnish. But I could be missing something. Would you suggest something?