Summary:
Last night, I found that some of the input channels have wrong hardware filter switching(see elog #3842).
So, to check the whitening board(D000210), I swapped the one with ok switching and bad switching.
During the checking, I somehow broke the board.
I fixed it, and now the status is the same as last night (or, at least look like the same).
What I did:
1. Switching for SRM_LRSEN looked bad and every input channel for MC3 looked OK.
So, I unplugged the whitening board for SRM (1X5-1-5B) and plugged it into MC3's place(1X5-1-8B).
2. Ran WDWchecker.py for MC3. The switching seemed OK for every input channel, which means the whitening board was not the wrong one.
3. Swapped back the whitening board as it was.
4. Found MC3_ULSEN_OUT and MC3_LLSEN_OUT was keep showing negative value(they should be positive).
5. Check the board and found that one of LT1125 for UL/LL was wrong (broken virtual ground).
6. Replaced LT1125 and put the board back to 1X5-1-8B.
7. Checked the board with WDWchecker.py and dataviewer 5-hour minute trend.
The input signal came back to normal value(Attachment #1), MC3 damping working, input filter switching seems working
| before LT1125 replacement |
after LT1125 replacement |
C1:SUS-MC3_ULSEN_IN1: -2.4 dB [!]
C1:SUS-MC3_URSEN_IN1: 16.9 dB
C1:SUS-MC3_LRSEN_IN1: 15.4 dB
C1:SUS-MC3_LLSEN_IN1: -1.1 dB [!]
C1:SUS-MC3_SDSEN_IN1: 18.4 dB
|
C1:SUS-MC3_ULSEN_IN1: 18.2 dB
C1:SUS-MC3_URSEN_IN1: 17.6 dB
C1:SUS-MC3_LRSEN_IN1: 16.6 dB
C1:SUS-MC3_LLSEN_IN1: 17.1 dB
C1:SUS-MC3_SDSEN_IN1: 16.2 dB |
Result:
The whitening board seems OK.
The wrong one is either wiring or RT model. Or, the checking script.
|