Secondaries on a new mains stransformer broken?

[dc197]

Greetings gents
I'm new here.  Hi.

I'm making a pedal. It's Ron Black's tube distortion, and so needs mains power according to the specs.

I soldered the primary windings of the transformer to the mains jack and tested it. I got 13V out of one of the secondaries, as expected. No problem.

Then I installed the transformer into the case, bolting it in using the hardware supplied.
I then tested it again and found that suddenly nothing works.
No output from either secondary.
The DC resistance of both secondaries, instead of being a few ohms as it was before (I measured), is now that of an open circuit (ie infinite reading on the multimeter).

It looks like when I screwed the transormer into the case, I somehow broke the seconarry coils. Does this sound likely? I used the rubber isolators supplied, and didn't over-tighten the bolt (I don't think).

Could I have somehow broken the wires of both secondaries inside the transformer? It seems unlikely but I cannot think of another explaintion.

Any thoughts? Should I take it back to the shop?

Thanks
Dan

[R.G.]

If you are certain that you are measuring the resistance of the secondaries correctly (that is, you have measured the right wires) then yes, the transformer is broken and you should return it. And your description does sound like you're doing it correctly.

But I agree, it sounds very unlikely that simply bolting the transformer into the chassis would break the secondaries. Just because it is so unlikely, I would check it again, then remove it from the chassis and check it again to be sure to eliminate some error in measuring.

But if the transformer really opened the secondaries from bolting it in, it is really defective.

Is it possible that there is a thermal fuse inside the transformer and that you may have shorted the output when you bolted it in, causing the thermal fuse to open? That's far fetched too, but more likely than mounting it breaking the wires.

[dc197]

OK, thanks, I'll do that.