Thanks to all those who responded. A summary of responses is given below.
How we solved the problem: I tried all resets and changed several boards
sent by Bruker. One of them was the HPPR cover module. The problem still did
not go away. A Bruker Engineer tried to solve the problem on-site, but
during that process several other things broke. Eventually the AQS bay with
power supply had to be replaced. I am not sure what finally solved the
problem because the only things that we really replaced are the AQS bay with
power supply and HPPR-1 cover module.
-Gopal Subramaniam
Here are the suggestions given by other colleagues at AMMRL. Thanks again.
1. If you have a scope, start by looking at the 1 Volt output to the power
amplifier. HPPR-1 is the preamp box on the floor near the magnet. If you
are getting the required voltage to the power amp for all channels then the
transmitter part is okay. If you don't get approx. 1 volt, try going
backwards to other boards and check their inputs.
Sandip
2. The power supply of AQR feeds also the HPPR. Have you checked the leds at
the back of the AQR? If they are ok, it does not necissarily indicate that
everything is ok in the power supply. If the fans of AQR have died, the
temperature may kill 100u capasitors in the power supplies of AQR, and leds
not necessarily react on this failure.
All the best
Petri
3. Did you check the preamplifier?
JOE
4. WE have had this occur under several circumstances on
our various spectrometers:
Usually it is just a matter of rebooting spect via software, not
a hard turn off.
Always it requires a 'cf'
Twice it has been a dead HPPR....always with an red error
light on the preamp itself.
Pax
Charlie Dickinson
5. If you look at the back of the preamp, there is a very small and semi-
hidden red reset button. Try pushing that. I once replaced several of
the preamp's components before finding out mine was fine, once reset ...
good luck, Dave Vander Velde, University of Kansas
Received on Tue Nov 06 2001 - 19:07:47 MST