On Bruker probes, Jim Breeyear mentioned that one should not use methylene
chloride -- add chloroform to this as well! It can ruin QNP and BB probes,
and in-house repair is not always practical.
As far as cleaning the turbine, we often keep the eject air going, the idea
being that it might keep the junk from getting into the probe.
For cleaning stubborn stuff, I mounted an old plastic spinner on a wooden
dowel, and cut several grooves at an angle on both the barrel and the 45 degree
surface. The cuts tend to raise a bit of material, thus making for an
effective reamer. This works very well for removing dirt, which a kimwipe
or cotton does not catch, without removing the shims.
Regarding samples not falling into the probe properly, if the insert is broken,
proper shimming is usually impossible, most likely a bump will be on one
side of the main peak. Q-modulation can be due to a number of other reasons
(bad spinners, the balance of the probe tuning, coils having moved (for
whatever reason, perhaps extreme temperatures).
Also, the suggestion about marking the position of the Shim Stack is not limited
to turbine cleaning, if the stack should ever slip (e.g., as a result of prolonged
low temp runs) it will be much easier to get it back to the proper place.
Regards, Rudi Nunlist