Reports until 11:19, Thursday 24 March 2016
H1 CAL
kiwamu.izumi@LIGO.ORG - posted 11:19, Thursday 24 March 2016 - last comment - 18:36, Friday 01 April 2016(26229)
Pcal Y optical follower servo not functioning

Darkhan, Kiwamu,

We found that the optical follower servo (aka OFS) for the Pcal Y had stopped running. Pressing around some buttons on the medm screen, we could not make it back up running. We are suspecting some kind of hardware issue at the moment. According to trend data, it seems that it stopped running at around 18:30 UTC on Mar 18th for some reason. We will take a look at the hardware in the next Tuesday during the maintenance period.

Comments related to this report
jeffrey.kissel@LIGO.ORG - 18:36, Friday 01 April 2016 (26406)AOS
Link 

J. Kissel, E. Hall, [R. Savage via remote communication at LLO]

This was re-discovered again tonight. 
Opened FRS ticket #5241 so we don't forget. 
Email sent to E. Goetz and T. Sadecki suggesting they address on Monday 4/4.

Further information from our re-discovery:
Looks like Kiwamu had left the calibration line amplitude in a low / off state. We restored the line amplitudes to nominal, and it caused excess noise in the DARM spectrum (lots of lines, a little bit of elevated noise floor).
We don't see any sine-wave-like excitation in the OFS, TX, or RX PDs with a single calibration line on at reasonable amplitude (which is contradictory to elevated noise in DARM).
Rick suggests:
- Check the AOM.
- Check the shutter.
- Check that the laser hasn't tripped.