I have an old Powertap. The old standard model, maybe from 2000. I was getting some super-high readings that I know I wasn't putting out (like 1500 watts while pedaling easy, mostly right after starting) so I tried to zero the torque. I held select while in watts mode until "watts" disappeared. I held it again for a few seconds, like the manual says.
And now all I get are zeros for wattage. Transmission is fine - I can get speed like I always could. Batteries are new. I don't know why that went wrong, but can I undo what I did? Just going back to the inaccurate jumps would be better than nothing.