Hello all,
I'm really happy with the new home of this group since I think this makes it
much simpler to ask questions and search for previous solutions to problems.
I'm having a recurring issue with my 400 MHz Bruker Av I which works wonderfully
except for a recurring and sporadic issue that has been happening for
a long time. Data acquisition (even on 1D spectra) only partially acquire and
I get an error that is always some variation on "zg: rcuerror: Scan speed
overrides accumulation Increasing DW or D1, decreasing TD or switching off
the FID display may help fifo cycles: 191 done, 66 missed, Lock anomaly
during acquisition". This usually means that the acquisition only collected
part of the data, and then "something" prevented it from finishing.
The number of cycles finished/missed varies and sometimes this is accompanied
by strange erratic spikes in the lock signal that persist even after
acquisition has been manually stopped. I have replaced many boards on the AQS
rack in pursuit of this white rabbit (specifically the TCU, RCU, GCU, and even
one of the PSU units on the back) and while the frequency of the problems
seems improved, it still happens randomly.
Overall, acquisition still works ok with fewer NS and a TD0 of 4 (writes NS
to disk for 4 loop.) That way some of the data is saved and processed. Otherwise
it loses all the data. But I'd like to get to the bottom of this. Does anyone
have any insight about what I might do to fix this issue once and for all? 1H
spectra look really good on this system when it works and it's the only instrument
with an autosampler so it's used for high throughput and really a pain to have
to keep dealing with this. I wanted to keep this short but if anyone needs more
information about this specific issue let me know.
Best,
David O.
-------
David Onofrei, PhD
NMR Facility Manager
Chemistry Department
San Diego State University
work: chem-nmr_at_sdsu.edu
personal: donofrei2_at_sdsu.edu
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Received on Sun May 14 2023 - 20:50:02 MST