I asked for help a few weeks ago about a turbo pump A malfunction error on 
an old HP 4500 ICP-MS.

Johan Scijf has graciously offered to donate to the cause but I wanted to 
try and make sure that it was in fact the turbo pump before I had him dig 
around on the inside of his. We were having a slight oil leak in one of 
the rotary pumps so I wanted to get that fixed to make sure that it wasn't 
actually the problem. After repairing the rotary pump, the problem still 

So this is what basically happens when you try to pump the instrument 
down. The Vacum (BK) starts to pump down and then there is a click and you 
hear the spin of the turbo pump which immediately sounds as if it is 
slowing down and when it sounds as if it has come to a stop the error 
message comes up on the screen. I am guessing that since the turbo pump 
turns on that the controller is not the problem and it is really the pump 
but this is not very scientifically based theory so if anyone out there 
has any more technical ways to test this, I am all ears.

As always, many thanks for all of your help.

John Allen
Analytical Chemist I
Philadelphia Water Department
Bureau of Laboratory Services
1500 E. Hunting Park Ave.
Philadelphia, PA 19124-4941