Betsy, Travis, some Rich

While fighting to find the shorts in the ESD cable chain on the ITMy reaction chain, we discovered that the "pin 1" and "pin 5"  (or lower right and lower left) portions of the gold coating mask are shorted together via the metal suspension loop that runs along the underside of the optic.  My understanding is that this CP (CP-05) was reworked in order to reuse the mass with the proper wedge orientation.  Indeed, when I went over and looked at the ITMx CP (CP-01), I found it looks different since it was a newer model, not a rework.  Pictures were difficult to use to understand this shorting, so we instead defaulted to the second opinion of Rich Abbott who is visiting us this week.  He was in complete agreement of the gold shorting route across the suspension wires for the the lower left and right QUADs of the CP.

While laying on our backs in BSC1 staring at the CP gold coating short, we attempted to do a scrape test to see if we could scrape off some of the unused gold from one of the unused fingers on the under side of the optic (there due to the rework).  This seemed to kind of work.

While we chewed on this fix, I redirected RIch to the ESD 5-pin coax cable that plugs into the in-vac side of the feedthru on the chamber.  This has continued to be a problematic joint for us.  Earlier in the morning, just before we discovered the gold coating issue, we had one of the 5 cables (I think pin 2??) pull out very easily from the back of this connector, leaving the recepticle on the connector and the pin on the cable.  We were able to wiggle the pin back into place in the connector receptical, reseat the connector at the feedthru, and see that all 5 pins had continuity with Fil.  Rich points out that a solder joint is broken on this cable, and he (like us) is uneasy with the fact that it could pull out at any time - maybe why we've see it pass sometimes and fail at others over the last few days of short hunting.  Note, this ESD cable has been in chamber since the begining of install - it was installed in BSC8 prior to moving the entire SUS/ISI to BSC1.  This connector is well used and has an "old" history.

So, we've left the chamber to see what we should do with both of these problems.