Continued with hunting of ground loops at EY. After various attempts all shorts for ETMY are now fixed. Some of the steps taken to remedy shorts:
1. Betsy loosen and re-tighten some of the connections at the feedthru (in chamber).
2. Shorts on the UIM and PUM were no longer present. Short on ETMY MO still present. New short on MO/RO.
3. Disconnected cables at feedthru (air side) and verified pin 13 was not shorted to ground inside chamber.
4. Checked that the shield and backshell on connectors were not touching (feedthru air side).
5. Disconnected all cables coming from chamber at the SUS Amplifier boxes.
6. Checked that all pins and backshells were not shorted to chamber ground. All passed.
7. Reconnected all cables back to SUS Amplifier units.
Further to the above, Fil reported that he had not secured the cables connected to the 7 SUS EY Sat Amp boxes with their mating screws.
This morning, we ran the spectra again and see that all of the combs cleared up. So that is good.
However a new round of TFs (since Jim had the ISI unlocked and we were diagnosis something else), showed no coherence in the R0 Transverse DOF. This DOF uses only the Side BOSEM. This T TF was fine on Friday before all of the cable short remediation work. (Not sure why it doesn't reveal itself in the spectra...) So we think the actuation of the 1 OSEM is now broken.
Travis and I went down to EY this morning and secured all of the cables at the Sat Amp Boxes. The R0 T DOF still looked bad. SO, we went ahead and did a quick swap of the R0 Side BOSEM inside on the QUAD. Still no change.
Richard happened to be in the building - he power cycled the R0 Face1,2,3,Side Coil driver. Still bad.
We all broke for lunch.
For the record, the olds BOSEM that came off of R0 Side was s/n 083, the new one going in is 291.