Transfer functions on the fourth BSC-ISI showed some unusual resonances in corner 2 (figures 2013_01_10). I have attached transfer functions from the stage 1 actuators to the L4Cs and the stage 2 actuators to the stage CPSs. After checking/re-torque bolts in this corner and changing the Vertical L4C, the new set of transfer functions look good (figures 2013_01_15). This unit looks healthy. More details will be given in the testing report.