I tried rebooting megatron, to see if that might help, but everything still acts the same.
I tried using daqconfig and changed channels from deactiveated to activated. I learned by activating them all, that the daq can't handle that, and eventually aborts from an assert checking a buffer size being too small. I also tried activating 2 and looking at those channels, and it looks like the _DAQ versions of those channels work, or at least I get 0's out of C1:TST-ETMY_ASCPIT_OUT_DAQ (which is set in C1TST.ini file).
I've added the SENSOR channels back to the /csv/cds/caltech/chans/daq/C1TST.ini file, and those are again working in data viewer.
At this point, I'm leaving megatron roughly in the same state as last night, and am going to wait on a response from Alex.