Especially for MAT 252 users,

We have been using two MAT 252.
A few weeks ago, the maximum High voltage of one of MAT 252 failed 
down to less than 1 kV.
We could not recover normal HV anymore.
When we exchange the High voltage supply BEE board to the other one, 
the HV became normal (ca. 10 kV).
We decided that the HV supply board had been broken so that we 
decided to import a new one from Germany via Japanese Thermo Agency.

Today we exchanged the board to new one we received this morning.
The maximum HV, however, was still almost 0 kV.
We applied the new board to the other MAT 252 but the HV was 0 kV too.
All the five lamps on the board were always tuned on (normal).
The pilot lamp "LEAKAGE CURRENT" sometimes illuminated for a short 
period when we turned on the HV button on the board.

While the Japanese Thermo Agency are planning to import the other new 
board from Germany, we want to avoid wasting times for another 
several weeks until restarting the analysis.
We suspect that the setting of LEAKAGE CURRENT safety of the new 
board is too strict, because we can get normal HV when we use our 
original, non-broken board for the both 252.
If someone out there know the way to change the settings safely, 
please tell us.
We can see several variable resisters on the board.
Other suggestions will be greatly appreciated.

Sincerely,
Urumu
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Urumu Tsunogai, PhD
Associate Professor
Earth and Planetary System Science,
Faculty of Science, Hokkaido University
N10 W8, Kita-ku, Sapporo, 060-0810, Japan
Phone: +81-11-706-3586; FAX:  +81-11-746-0394
E-mail: [log in to unmask]
http://marchem.ep.sci.hokudai.ac.jp/index.html
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