The tube still glowed, so originally, I didn't think it was the fuse, but I did check it anyway. Swapped fuse from Tube 2 (which was biasing fine) to tube 1 and no change. Still no reading on tube 1. Thanks.
I have an RM100. It seems to play and sound great, but I wanted to try switching from 6L6GC power tubes to JJ EL34II tubes. I followed the instructions in the RM100 manual and checked the current 6L6 tube bias voltage. Tube 1 read 0 MV. I turned the screw both directions as far as it would...