While restoring OSEMs on ETMY, I noticed that the open voltages for the UR and LL OSEMs had significantly (>30%) changed from their values from ~2 years ago. The fact that it only occurred in 2 coils seemed to rule out gradual wear and tear, so I looked up the trends from Nov 25 - Nov 28 (Sundance visited on Nov 26 which is when we removed the cage). Not surprisingly, these are the exact two OSEMs that show a decrease in sensor voltage when the OSEMs were pulled out. I suspect that when I placed them in their little Al foil boats, I shorted out some contacts on the rear (this is reminiscent of the problem we had on PRM in 2016). I hope the problem is with the current buffer IC in the satellite box and not the physical diode, I'll test with the tester box and evaluate the problem further.

Chamber work by Chub and gautam:

1. Table leveling was checked with a clean spirit level
   • Leveling was substantially off in two orthogonal directions, along the beam axis as well as perpendicular to it.
   • We moved almost all the weights available on the table.
   • Managed to get the leveling correct to within 1 tick on the level.
   • We are not too worried about this for now, the final leveling will be after heater repositioning, ETMY cleaning etc.
2. ETMY OSEM re-insertion
   • OSEMs were re-inserted till their mean voltage was ~ half the open values.
   • Local damping seems to work just fine.