Hugh and I were concerned that safe.snaps were not current for all the chambers, so I took the disruptions caused by the PSL work as an opportunity to update I/ETMX, and HAMs 4,5&6, ISI's and HEPI's. HAM5 ISI has some weird masterswitch/dackill coupling, which we've seen before, but I paid more attention to what I had to do to make it work this time. Closing the master switch trips the dackill and the rogue excitation wd. The only way to recover the ISI is to turn on the masterswitch, reset the rogue excitation wd, then reset the dackill. Then guardian can take over and bring the chamber up. None of the other chambers I did required this. Very weird.