The servo for aligning the Y arm is working fine with the coarse gain coefficients.
However then I found the ASS_Xarm servo was not healthy.
So the next step is to refine the X arm servo in C1ASS.
+ With the ETMY oplev the Y arm became quieter after we recovered the oplev whitening filter (#5523)
+ The Y arm alignment scripts can be run from the usual C1IFO_CONFIGURE screen.
It will servo the spot positions on ITMY and ETMY, and align the input beam pointing. It brings the Y arm power to about 1.
+ The X arm servo is doing something funny. It doesn't bring the arm power up to 1.
I thought the X arm didn't need any modifications because the X arm servo doesn't include PZT1 and PZT2.
So it maybe a simple bug (for example, some switches are disable and so on)