Yesterday, ground loop checks revealed a new and random ground loop issue on the LR BOSEM of the Tip Tilt PM1 suspension (which has been installed and used in vac for a long while now). This morning I worked to swap the BOSEM for a new one, reset the medm offset/gains and recentered. Fil confirmed that the ground loop situation is now resolved on PM1. In Corey's absence, I took a bunch of photos (won't be as good as his but here for posterity) of the chamber components as we see them before closing up. I wiped down some of the under table surface as I could. Jim and I both inspected for left behind items on and under the table. BOSEM SN 263 is the problem OSEM removed, SN 229 was swapped in with OLV 28860. Jim then removed the septum viewport covers (all 4)and unlocked the ISI. Oli ran the final closeout TFs for PM1 (JM1 and JM3 were yesterday). I revisited the closeout check sheet and we launched the door crew (Jordan, Randy, and FAC - thanks for jumping in due to others absences!). 1 door is on now and we are about to check that the JAC Refl beam goes through the viewport on the door as anticipated given the inaccuracy of the viewport simulator fixture.