According the logbook 44429, the SIB2 bench was opened to install some attenuators of the quadrant DC channels .
During this intervention one can observed a drift only on all the SIB2 DBoxes timing error channels:
- SIB2_DBOX_RightDown_timimg_error: +200ns
- SIB2_DBOX_RightUp_timing_error: +60ns
- SIB2_DBOX_LeftDown_timing_error: +30ns
- SIB2_DBOX_LeftUp_timing_error: +30ns
The RFC and B2 demodulation mezzanines are in the SIB2_DBOX_RightDown DBOX . The 200ns jump could explain the B2 and RFC phase tuning needed to re-lock the ITF
Nervertheless, the causes of these jumps are not yet understood