Hi Everyone;
A couple of weeks ago I wrote concerning the SMS 50 sample changer on our 400MR crashing
after retrieving a sample from the magnet. I would like to thank Roger Kautz, Alan Ronemus,
Chris Rithner, Ryan McKay, David VanderVelde, Jerry Dallas, Craig Grimmer, Yevgeniy Chernioglo,
and Ghirmai Meresi for their help and advice. Some of the suggestions were:
Installing the 103 patch.
Problems with the NMR tubes (parafilm, short tubes, etc.).
Replacement of the sample changer internal potentiometers (I have been told that this would result in jerky movements.)
An electrical control cable damaged from flexing at the same point.
In order for the sample changer to load a sample, it must NOT sense a sample in the magnet:
this requires that the lock level drop to zero, and that the "Present" led on the box at the top
of the magnet be OFF. What seems to have solved our problem was cleaning the upper barrel
(and therefore the sensor that detects whether or not a sample is present in the magnet);
checking the electrical connections on the PFE board that interfaces with this (in our instrument
it is at the back left side of the Pneumatics / RF Front End when looking from the back of the
console); and adjusting the potentiometer that controls the sensitivity of this sensor.
(The potentiometer location apparently depends on the instrument age/version; it may
be at the back of the console, or possibly on the front; in ours it is on the PFE board in the
front left corner when looking from the back of the console.)
Thanks again to all!
Karl Koshlap
Received on Wed Mar 20 2013 - 06:07:11 MST