[Terrence, Ushiba]
Terrence worked for the damping controls of ETMY and found that the transfer function from MNP excitation to MNP motion measured by photosensors seems strange (fig1).
So, I checked the history of the transfer functions and at least TF seems healthy in the last year (fig2).
Then, Ifound that photosnsor V3 has very small signals (about -300 cnts), which should be about -3000 cnts.
Accordingto the photosensor signals, MNV3 photosensor output changes on 12 of January around 15:00 JST (fig3).
On that day, some works around EY was done (klog19421 and klog19425).
So, tower part, especialy at IP stage, needs to be checked.
