Fluke 5725A, Instruction Manual, Page: 108 / 196

5725A
Instruction Manual
6-8
CURRENT MODE
5725A STANDBY
FAULT
OVERLOAD
CABLE OFF
POWER
11A
MAX
2OV
PK
MAX
LED
CR317
TP301
FRONT PANEL
TP307
TP304 LED
CR318
HIGH VOLTAGE
AMPLIFIER
(A3)
POWER SUPPLY
(A4)
aq16f.eps
Figure 6-4. Initial Access Procedure
6. Verify that both LEDs CR317 and CR318 on the Power Supply assembly (A4) are
off. If either is lit after three minutes, there is a fault in the high voltage capacitor
bleed-off path. Do not rely on an off condition as an indication that dangerous
voltage no longer exists on the filter capacitors.
Warning
Do not rely on the power supply leds as an indication of the
presence of high voltage. Always use a voltmeter to check for
high voltage between TP307 and TP301, and between TP307
and TP304.
7. To confirm that high voltage has dissipated, set a DMM to the 1000V dc range, and
take a reading with the common lead to TP307 and the high lead to TP301 on the
Power Supply assembly. This is the +400V filter capacitor test point, and it should
be at a safe level near zero.