The following Triple Acquisition driver noise monitor boards were replaced per ECR E2300035.
Beam Splitter (Rack SUS-C5, U26):
Chassis Serial Number S1100039
Old Monitor Board MON156
New Monitor Board S2100109
SRM M2 (Rack SUS-C7, U26):
Chassis Serial Number S1100035
Old Monitor Board MON177
New Monitor Board S2100483
SRM M3 (Rack SUS-C7, U22)
Chassis Serial Number S1000356
Old Monitor Board MON128
New Monitor Board S2100108
Placement of rear LEDs (DS1 & DS2) on new boards prevents board from sitting flush to rear panel. While this does not prevent new boards to be installed, use caution as not to damage the connector threads.
F. Clara, M. Pirello
Jenne, Jeff K, Ryan S, Rahul
This afternoon during IFO locking attempts Jenne and RyanS were facing issues with SRM (was behaving inconsistently). At first I glanced the medm screen of SRM and couldn't find anything which could suggest issues. We also used time machine compare settings. Next we took a set of transfer function measurements on M1, M2 and M3 stage and this is where we found issues at M2 and M3 stage. The TF results did not match with that of the reference and was noisy.
At this point Jeff asked me to drive the M3 stage coil output filter of SRM with a sine wave (0.1Hz frequency, with an increasing gain). We could see the drive in the inmons but the noisemons were not showing anything. Jeff then went to check things out with Fil and found some cables disconnected at the triple acquisition driver noise monitor M2 and M3 stage. Once those cables were connected, the TF for M2/M3 stage looked fine and also the voltmon was showing some activity and the issue was solved.