Hot and Crackling Power Transformer

I have been reworking this amp I bought on ebay but once I fired it up not all the tubes heaters were glowing and the power transformer was making a crackling sound. I turned the amp off right away and the Power Transformer which was on for not even a minute was extremely hot to the touch. I pulled the rectifier tube and then all the tubes to check voltages on the secondaries and they were really low, plus the same crackling sound and hot transformer occurred. Do I have a bad transformer here? Bad ground? What do I need to check to know for sure it is a shot transformer and not something I screwed up? Thanks in advance.

Jesse

Disconnect the various output windings, especially the high voltage one, and see if you still crackle.

It probably is a bad transformer, unfortunately.

probably internally shorted but you never know... it came from EBay

Worst case replace it with a antek toroid unless space and weight would be a problem.

Look around Geofex there is a transformer tester circuit there

Well, I ordered a replacement transformer for the amp and it fired up just fine. The transformer was indeed shot it seems. I will now be taking it apart to see what the failure is. How easy is it to fix broken transformers? Thanks for all the help.

Not easy, usually. Quite messy, as typically the short is buried in the carbonized crud deep in the interior of the windings. Dissect to learn, not to salvage, would be my advice.