Jim will bring three proximity masks to Brandeis. Their serial numbers are
C0420, C0417, C0416. C0420 "died" after some hours of running on the sector,
but when we replaced it and tested it on a test stand, it was working again
(the test was done 3 days after replacing it). C0417 and C0416 died after
approximately 24 hours of running on the sector, and were still dead when
tested on the test stand. Maybe you can find out why/how the latter two died,
and if something is strange about the first one. C0416 and C0417 were connected
to the same multiplexer, while C0420 was connected to a different one.