Sheila told me that a couple of OSEMs on the ETMY M0 stage were reading almost zero values. Since ETMY is a key for the upcoming DARM locking, I tried fixing them.

I went down to EY and spent some time trying to understand what is causing it. Finally I found out that this was due to a loose connection at a DB9 connector on a QUAD coil driver (D0902747).  Since I was standing in front of the electronics rack with a flat top screw driver in hand, I tightened every DB9 connector which was in the same rack. This should increase a chance to detect gravitational waves.

Some detailed notes

• I used D1002741-v6 for tracing the cables
• The loose cable is CAB:H1:SUS_ETMX_10
• The malfunctioned channels are M0_F1, F2, F3 and SD. They are exactly the channels that the loose cable is supposed to send to the ADC0.
• TOP coil driver S1000300.
• LED MON was very useful to determine if the signal arrive at the coil driver.