1. 2009: restart the system: few observations. Hw maintenance week:
HW Maintenance – JANUARY 2009
Outline:
2009: restart the system: few observations.
Hw maintenance week:
- The devices to repair.
- The checks.
TRIG_PGA: the status.
S.Monteil
PS/SPD COMMISSIONING

2. 2009: restart the system: few observations.
HW Maintenance – JANUARY 2009
2009: restart the system: few observations.
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). HLT dysfunctionned due to a FEST test. Fixed after we left. No data recorded.
4) Evgueni G. and Anatoli K. can now work on LED light yield uniformization.
S.Monteil
PS/SPD COMMISSIONING

3. HW maintenance: latest observations.
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. They rest in peace now.
S.Monteil
PS/SPD COMMISSIONING

4. HW maintenance: C-side actions.
HW Maintenance – JANUARY 2009
HW maintenance: C-side actions.
1) Two malfunctionning VFE boards:
SM3-T01,
SM1-T03.
Actions:
Check clock connection.
Check the power supply connection.
Replace the boards if necessary.
Remeasure their pedestals.
S.Monteil
PS/SPD COMMISSIONING

5. HW maintenance: C-side actions.
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.
Actions:
For the former, plug/replug the cable.
For the latter, we already decided to live with that.
S.Monteil
PS/SPD COMMISSIONING

6. HW maintenance: C-side actions.
HW Maintenance – JANUARY 2009
HW maintenance: C-side actions.
3) One PMT base has a too large current consumption. (SM2-T03). But no effect observed on cosmics data.
Action:
Change the board. Check whether consumption decreases.
If the measured current is related to light entering into the tube, we’ll lose it at some point. Better to change it.
S.Monteil
PS/SPD COMMISSIONING

7. TRIG_PGA: the status. HW Maintenance – JANUARY 2009
I remeasured for two crates the ranges of phasers sampling the ECAL data after installation of ECAL-FEB w/ new serializers. Basically no change. Even better in few cases. Not an issue.
Hervé looked at a redesign of the TRIG_PGA in case the trigger path commissioning results of 2009 requires to reprogram. So far, two achievements:
One clock cycle might be saved in the current architecture. Anecdotic.
Grouping all data in the center of the chip to uniformize sampling time (LAL empirical advice) improved the sampling of one ECAL data and degraded the other. It seems that Rémi followed an opposite recipe. No obvious path. Tries and fails.
S.Monteil
PS/SPD COMMISSIONING