Dead OT?

[rdrinkwater]

I've been lurking here for a couple of years and after deciding that a real Wreck would be too loud, I built an AX84 4-4-0 last year. Great little amp, a lot of fun.

... however, even that proved to be too loud. So, I put a simple L pad attenuator between it and my cab.

After tinkering with the attenuator this afternoon, and introducing a wiring fault by mistake (probably open circuit to the OT) and firing up the amp I realised my error and turned it off. However, something was damaged in the process. Can anyone advise how to go about debugging this please? I have read for resistance over the OT primaries and it looks like a short circuit... Is it likely to have taken out my power tube as well?

Any help appreciated...

[Structo]

What was your wiring mistake?

It usually takes more than a briefly unloaded OT for it to fry.

Are you getting any output at all?

[rdrinkwater]

Yes, should probably have said, there is still some output, but really quiet.

I'm not certain what the mistake was - I think either open or short. I've fixed it now...

[pdf64]

I have read for resistance over the OT primaries and it looks like a short circuit

What reading are you getting?
Do you have a 'before' reading?
If not, what's the manufacturer / specs of the OT?
Pete

[rdrinkwater]

It's a Hammond 125C. I don't have before reading, currently I am seeing:

Primary I see about 270 ohms. Secondary I get about 1 ohm between pins 4 and 6.

So not a short circuit. Think that may have been panic

[Structo]

Yeah the secondary on that transformer will be a low reading.

If it was fried you probably wouldn't get a reading at all, open circuit.