Hello,
Several people had answered my question (below) and most of them suggested that our problem is related to overheating of the transmitter. We have opened the console power supply and the B-LT-4 (transmitter unit). We've removed significant amount of dust from both and replaced both fans in the console power supply - one of them was VERY noisy. The fans in the B-LT-4 seem to be OK - we've checked their rpm. Unfortunately, after this "repair" we completely lost signal! Before we could not observe tuning signal but it was still possible to run data acquisition. Now there is nothing!
If I enter the "ii" command I get the following message:
"acqerror: problems during MCI initialization
channel 1 bit 0 load/readback failed
program stopped"
Running "wobb" gives the following error (it used to display VERY noisy curve):
"The measured signal is too weak.
Check the spectrometer harware"
I think we've accidentally disconnected something during "repair" or maybe this is a significant new symptom...
Thank you for your help but I definitely need more!
Piotr
PS Yes, we are still running XWINNMR 1.3 (all possible patches installed). There is nothing we can do about it without a major hardware upgrade.
Piotr Dobrowolski Ph.D.
NMR/EPR Manager
Department of Chemistry & Biochemistry
Utah State University
0300 Old Main Hill, Logan UT 84322-0300
telephone: (435) 797-1673
fax: (435) 797-3390
http://www.chem.usu.edu/pages/facilities/nmrfacility.html
________________________________
From: Piotr Dobrowolski [piotr.d_at_usu.edu]
Sent: Friday, September 28, 2007 16:09
To: AMMRL (ammrl_at_chemnmr.colorado.edu)
Subject: AMMRL: ARX tuning problem
Hi everybody,
We are experiencing a problem with tuning of the 400 MHz Bruker ARX (BBO probe). After setting up the experiment and starting “wobb” (XWINNMR 1.3) all we can see on screen is noise. So far we’ve observed it for 31P, 13C and 2H and it is sometimes (not always!) accompanied by similar problem with high frequency (1H) tuning. The problem can be usually fixed by restarting of the system (reviveccu) and/or reloading acquisition parameters and trying to “wobb” again. Today we had to shut down the entire machine and start it again after few minutes. Initially we were able to tune only the high frequency channel but then it “fixed itself” and we could observe the tuning curve for the low frequencies. Really confusing! Can this be related to some hardware malfunction or is this just another XWINNMR bug?
Thanks,
Piotr
Received on Mon Oct 08 2007 - 12:07:37 MST