[Elecraft] K2 lost sidetone?

[Jeff Kinzli]

Oh man, what timing...2 hours before the start of the contest, and I
went in and did CAL tPA to set the ambient temp of the KPA100, and
when I came out of the menus, I had no sidetone anymore!

Going through all the menus, all the side tone settings look correct.
The rig hears and transmits fine, but the sidetone is silent.

I thought I might need to reset back to defaults, but I think that
resets all the filters and BFO, etc., right? If that's the case, I've
gotta go through realignment again? I'll miss the beginning of the
contest :( I'm going to miss it anyhow though at this point.

Any ideas short of disassembling and resetting?

Thanks,
-J