Dear group,
I have a very old Bruker DRX 500 that was working beautifully until
yesterday. It now has a very puzzling problem. Here's a timeline of what
happened, and a description of the current state:
The console is a DRX installed in 1996. The computer is CentOS 5, and
I'm running Topspin 1.3, for which I don't have a license.
Yesterday a user came to me and said that topspin wouldn't start. It
apparently couldn't see the spectrometer, and wouldn't start because it
doesn't have a license. I've seen this thousand of times before, so I
assumed that the CCU had died and just needed to be reset, but much to
my surprise I was able to telnet to it. I don't remember ever seeing
that before.
First, I just reset the CCU. But then it wouldn't boot. I tried
resetting it several times, then power cycling the AQX, and doing the
full reviveccu routine. But it would never boot. I could never connect
to it with telnet.
I eventually swapped in a working CCU from another DRX 500, and that one
had the same problem - it wouldn't boot. But then I left to go do
something else, and came back about 30 minutes later and tried again,
and this time it was different. First it connected (but hung just before
the login prompt). When I eventually killed that, I tried again and the
second time it got to the prompt and I could type 'root', but then it
hung. I killed it again, and on the third try it worked normally. I
could log in (and I could also start topspin).
Since all this happened, I've put back in my original board and verified
that both boards give exactly the same behavior. Both take about 30
minutes to boot, and both give rise to the same behavior within topspin.
So everything I'm going to describe now is true for both boards:
I tried to run 'cf'. It worked fine, except that it can't find any
amplifiers ("ACB did not find any amplifiers"). This happens every time.
I've tried everything I could think of. I ran 'acb' in a terminal and
did everything obvious in there. I ran the systest stuff in spect. I
reset the ACB board with the little recessed button (well - Bob Taylor
did that - he's been helping me). I tried making a new configuration.
Nothing will make it see the amplifiers.
But here's the really weird thing: everything actually works. It can
lock, tune all channels, and pulse (at least proton - I haven't tried
the other channels yet). And everything seems normal. Right now the only
downside is that the lights on the keypad that indicate pulsing don't work.
I thought it must have something to do with the CCU, but both CCUs give
the same symptoms. It's hard to believe that something is wrong with the
ACB, because the amplifiers actually do work. It must be some
communication problem inside the console or something. Another thing is
that everything involving the CCU seems very slow. It always takes ~15
minutes to boot. And when I ran some of the u/systest stuff, things took
a lot longer than usual.
Anyway, if anyone has any insights or any ideas, please let me know. I
will post a summary.
Thanks in advance!
-Robert
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Robert Peterson, Ph.D.
Facility Manager - NMR Technology Center
UCLA-DOE Institute for Genomics and Proteomics
UCLA Dept. of Chemistry and Biochemistry
phone: (310)825-1816
fax: (310)825-0982
peterson_at_mbi.ucla.edu
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Received on Thu Jul 01 2021 - 14:17:32 MST