[mithrandir (Andrew)]

While I was observing tonight - about 15 images into a run, the handpiece display suddenly started rotating through the function list you get when you press and hold the Menu key. PHD could still guide so I let it finish the run before fiddling.

The Gemini would respond to commands through the RS232 from the computer, but nothing short of powering off would break the handpiece out of the loop. I got the computer to park the mount at CWD, powered it off, powered on said I wanted a warm start, chose Achenar to align (almost dead centre) and before I could use the menu to tell it to synch it went back into the loop.

I took the Gemini inside, pulled the backup battery (just over 3V) and replaced it with a new one (about 3.2V). After putting it back on the mount, connecting the GPS, resetting the mount type in SRAM and restarting, a few minutes later it went back into the loop.

Any guesses which bit is most likely at fault?

It was VERY humid - the whole rig was dripping wet - so I wonder if that had anything to do with it, but last night was just as wet and I had no problems.