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ÚÚÚ
PROPRIETARY and CONFIDENTIAL
ÚÚÚ
SERVICE
BULLETIN
Instrument:
Humphrey Field Analyzer II-i
No.:
FA2i-018
Subject:
Power Supply FET Failure
Date:
9 May 03
Status:
Informational
Pages:
1
Problem
The FETs (power transistors) in some HFA II-i power supplies may fail prematurely.
Cause
Fluctuations in the line voltage of the instrument, that exceed specified levels, may cause degradation of
the FETs.
Solution
To prevent this from happening, the power supply vendor has increased the rating of the affected FETs
from 400V to 500V. We have also implemented new power supply testing procedures on the production
line.
The serial number ranges, of instruments that may be affected, are listed below. Not all instruments within
the serial number range will be affected.
720i-5454 to 720i-5553
740i-10348 to 740i-10870
745i-4380 to 745i-4433
750i-8903 to 750i-9113
Power supplies should only be replaced on failure. Credit will only be given for failed power supplies,
which have been returned to CZMI for inspection.
Summary of Contents for humphrey HFA II-i series
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Page 424: ...Page 4 FA2i 013A PROPRIETARY and CONFIDENTIAL...
Page 502: ...FA2i 041 Page 3 Figure 2 Press rectangle in Top Left corner...
Page 516: ...Page 2 FA2i 046 Figure 1 Glass Film Wedge Detectors P N 67417 Note Spacing Washer Placement...
Page 517: ...FA2i 046 Page 3 Figure 2 Y Motor Turret Detector P N 67418 Note Spacing Washer Placement...