Keysight e3620a, Operating And Owners Manual

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A-5
Figure A-7. Load Transient Response Time Waveform
TROUBLESHOOTING
Before attempting to troubleshoot the power supply, ensure
that the fault is with the supply and not with an associated
piece of equipment. You can determine this without removing
the covers from the power supply by using the appropriate
portions of the "Performance Tests" paragraph.
Before applying power to the supply, make certain
that its line voltage selector switch (S1) is set for the
line voltage to be used.
Open Fuse Troubleshooting
Although transients or fatigue can cause a fuse to blow, it is a
good idea to inspect the unit for obvious shorts such as dam-
aged wiring, charred components, or extraneous metal parts
or wire clippings in contact with circuit board conductors
before replacing the fuse. The rating of the correct replace-
ment fuse depends on the line voltage option of the instru-
ment: for Option OE3, use a slow-blow 1 amp fuse and
standard and Option OE9, use a slow-blow 2 amp fuse.
ADJUSTMENT AND CALIBRATION
Current Limit Adjustment
To adjust the current limit circuit in the V1 or V2 supply, pro-
ceed as follows:
a. Turn the current limit adjustment pot (R63 for V1 supply
or R34 for V2 supply) to fully counter clockwise.
b. Connect the test setup shown in Figure A-4 to the output
of the supply to be adjusted. Substitute a short for R
L
and
leave load circuit switch open.
c. Turn on the supply and set the VOLTAGE control for max-
imum output(fully clockwise).
d. Close load switch and adjust the current limit pot (R63 or
R34) until the DVM indicates a voltage drop across the
shunt of 0.1 V + 5% (0.105 V).