Second, the upper stack and lower stack( RT shims ) screw together with a
big ( bore size ) thread. If memory serves, the RT shims have the female threads
and the upper stack has the male threads. I thought the upper stack was made
of Al tubing not PVC, but things may have changed since I was working on QEs.
With the upper stack and RT shims separated, you should be able to put a small
finger up from the bottom with an acetone wet kim-wipe and clean the spinner
shelf. Feel it for sticky spots AND bumps. Big bumps in the spinner shelf may
be bad places in the Al spinner shelf and they will need smoothing with fine
sandpaper. With the upper stack out and cleaned you should be able to drop a
sample tube in a spinner down and try to get the sample to spin. After it spins
with the upperstack separated, try screwing on the lower stack ( again out of the
magnet ) and confirm spinning. Now remove the sample and add a probe. Lower
a sample into the assemply and hold vertically. The sample should spin at this
stage. If it does not spin then there is one of two problems:
1) probe/upper stack/RT shim alignment.
2) broken probe insert.
Fiddling around can usually fix the first and a probe repair is required for
the second.
Once everything works out of the magnet, reassemble inside the magnet and
confirm alignment and spinning. Then put the sample changer back on and
get the alignment and seals working and your done.
==============================================================
Virginia W. Miner gina@acornnmr.com
Woodrow W. Conover woody@acornnmr.com
Sam Le Chien sam@acornnmr.com
Acorn NMR Voice (510) 683-8595
46560 Fremont Blvd., #418 FAX (510) 683-6784
Fremont, CA 94538-6491