Ground loop caused DAC channel to go out--what is likely to have happened?

[Grindstaff]

Hello,

This is my first post here. I'm a big fan of Eico tube amps (hf-81, hf-12).

I have an EAD Theatermaster Ovation Plus DAC (or pre/pro rather) that I've been using for stereo audio. Please have an open mind about that, it really sounds quite good.

I'm not really a home theater person, but this weekend I thought I'd set it up as such and use all tube for the amplification.

Due to some ground loop (I felt the shock), my right channel no longer works. All the other 5 channels do.

What is likely to have happened? A resister burned out? I don't want the fix to be expensive, of course.

In stereo mode, one can use the balanced outputs as well as the unbalanced. For that right channel in stereo, both the balanced and unbalanced do not work (just a faint hum).

Of course, I've checked the amp and switched things around to verify it is the Theatermaster.

Any ideas are welcome. I've got pictures of the open unit if anyone would like to take a look. Thanks.