[RASMB] CPU Board Malfunction on XL-I

[Deborah Pheasant]

Hello, all,
Just to add another experience to the discussion, our XL-I bought in 2000 had these stoppages of either scanning or spinning during the summer months when electrical load was high on campus.  We installed a power conditioner which fills in line voltage dips and our problem has disappeared.
Regards,
Debby

From: rasmb-bounces at server1.bbri.org [mailto:rasmb-bounces at server1.bbri.org] On Behalf Of Ute Curth
Sent: Friday, March 11, 2011 6:05 AM
To: rasmb at server1.bbri.org; ian.berke at yale.edu
Subject: Re: [RASMB] CPU Board Malfunction on XL-I

Hi Ian,
we bought an XL-I equipped with an Aviv AU-FDS in 2008 and also suffer from severe problems. Either the centrifuge stops spinning or the computer stops scanning within a run. This happens after unpredictable times (20 min to 20 hours), at different rotor speeds (e.g. 22, 35 or 50 krpm), independent whether we measure absorbance only or absorbance and interference but not in every run. Our machine is still under warranty and Beckman has been trying for more than one year to solve this problem. A lot of components of the machine (all boards, the display, the radial drive....) were exchanged, but this did not solve the problem. After having ruled out that there were problems with the power supply in our institute, they admitted that there is a timing problem in the communication between centrifuge and computer and that similar problems exist in about 10 machines worldwide. Therefore, they modified the firmware and installed a new firmware pre-release (now the machine stopped scanning regularly in runs which were performed at 50000 rpm) and afterwards a new version of the GUI, which should solve this problem. In first tests with the new firmware/GUI combination the machine seems to work more reliable (it did not stop in several test runs at several speeds), but it turned out that the new firmware is not able to hand over the correct value for w^2t to the computer (a plot of w^2t against the time is not linear as expected, but looks like a saw tooth wave).  They are trying to solve this problem for several weeks now and I still hope that our centrifuge will work properly soon. Just as a comment: the Aviv fluorescence detection system works without any problems.
Best wishes
Ute

--

PD Dr. rer. nat. Ute Curth

> Medizinische Hochschule Hannover

> Strukturanalyse

> OE 8830

> Carl-Neuberg-Str. 1

> 30625 Hannover

> Germany

>

> Tel.: +49-511-5329372

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