S.MonteilPS/SPD COMMISSIONING1 HW Maintenance – JANUARY Clermont team Outline: 2009: restart the system: few observations. Hw maintenance C-side: - The devices to repair. - The checks.

S.MonteilPS/SPD COMMISSIONING2 HW Maintenance – JANUARY : restart the system: few observations. 1) Power rectifiers changed. We checked that each module of interest for us powers correctly. A reboot of RCM crates was necessary. 2) HV system repaired and reinstalled (and calibrated): it worked fine. 3) LEDs: we saw light in the DAQ. This is a way to say that the entire slow control chain was used. Several problems here and there overcame (as usual). Online system for standalone detector Run Control was made unstable by the FEST test. 4) Evgueni and Anatoli took over (see corresponding talks).

S.MonteilPS/SPD COMMISSIONING3 HW Maintenance – JANUARY 2009 HW maintenance: latest observations. We performed systematic pedestal measurements and connectics checks for the whole A-side and C-side. They exhibit the same problems as before. In addition, we lost the PSFEB07 half-board (VFE SM1-T03). Pedestals were wiggling in a recent past.

S.MonteilPS/SPD COMMISSIONING4 HW Maintenance – JANUARY 2009 HW maintenance: C-side actions. 1) Two malfunctionning VFE boards:  SM3-T01,  SM1-T03.  Symptom: a half-board KO. Fix:  The malfunction was related to unstable LV supply: -0.3 V w.r.t the nominal one. The VFE electronics shall anyway work under these conditions. Most likely, oscillating LV.  Touching, pushing, blowing on the corresponding fuse restored the nominal LV.  We have to think hard about a more robust patch panel.

S.MonteilPS/SPD COMMISSIONING5 HW Maintenance – JANUARY 2009 HW maintenance: C-side actions. 2) List of malfunctionning or dead channels ([Feb,Ch] Matrix):  [23,28], dead channel. Guess: bad VFE connection.  [53,24], large pedestal : 263. Fix:  For the former, plug/replug the cable. It actually came back to 270. Still high but as previously.  For the latter, we already decided to live with that.

S.MonteilPS/SPD COMMISSIONING6 HW Maintenance – JANUARY 2009 HW maintenance: C-side actions. 3) One PMT base has a too large current consumption as indicated by the HV control readout. (SM2-T03). But no effect observed on cosmics data. Actions:  Change the board. No effect.  It was a fake observation.  Anatoli is investigating.  The initial board was reinstalled.

S.MonteilPS/SPD COMMISSIONING7 HW Maintenance – JANUARY 2009 CONCLUSIONS 100% of the C-side channels are functionnal. We have to think about improvement of the VFE-LV patch panel distribution.