While doing charge measurements I noticed that the power supply to the ESD was off I went to the end station Y to check it and I turned it back on (recalling setting 01 on the power supplies as per instruction given few days back). Later I turned the ESD HV amplifier On (as per previous instructions) and verified insitu that it was not railing. It is working fine now.

Notice also that the ESD LL quadrant cable is back to the proper configuration so at the moment LL quadrant cable is going directly from the resistor box to the feedthrough while BIAS is going through the ESD LP filer box. This was done at about UTC 2014-08-15 23:00:00 and after doing this we verified that the ESD was not railing and that we were able to drive the quadrants so I do not believe it is related with the ESD power supplies turning off. Maybe another power glitch?