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User name mcnulty
Log entry time 12:09:14 on June 08, 2010
Entry number 325265
keyword=Investigation of counting DAQ quartz det signal problems in Rarm
Made opportunistic access to trouble shoot the problem seen during the
last Q2/alignment study. The problem was the lower (amplified) quartz
signal was crazy-looking and the upper quartz signal was not well
separated from pedestal.
I found the amplified signal cable connector was sagging at the fastbus
ADC; I re-inserted it and the problem is fixed.
I noticed the upper quartz signal was working, but had a huge 10ch
pedestal. I examined 5 other channels in the group of 16 (of the ribbon
cable) and found all of them to give between 9 and 10ch for pedestal RMS.
This is perhaps the problem since the quartz signal is only 30 or so
channels above pedestal...a 10ch pedestal is bad. I did not have time to
try another group of channels or another ADC slot, but we should perhaps
do this during an extended down.
I restored all signal pathways and HV values to their nominal
settings...set for integration DAQ mode.