Fluke 5725A - Manual (Page 139)

Troubleshooting
Testing the Power Supply By Itself
7
7-9
3. Remove plug P301 from J301 and inserting it into J303. Now the high voltage power
supply will power up in the
±
50V mode. The high voltage amplifier may also be
serviced in the
±
50V mode.
7-10. Testing the Power Supply By Itself
To turn on a Power Supply assembly (A4) by itself for troubleshooting, proceed as
follows:
1. Turn off the POWER switch and disconnect the line power cord from ac line power.
Warning
Follow the instructions under "initial access procedure" in
section 6 to make sure high voltage has been bled off before
you touch anything inside the 5725A.
The power supply assembly generates lethal voltages. Use
extreme caution when you are working inside the 5725A with
the power connected. Use only non-conductive tools, and keep
one hand behind your back to avoid making a circuit through
your body. If you work on a 5725A with the power cord
attached, and/or you are not certain the high voltage has not
bled off, do not wear a grounded wrist strap. Wearing a strap
increases risk of dangerous electrical shock.
2. Place the Power Supply assembly in the service position as described in the access
procedures in Section 6.
3. Plug P301 onto the E302 header where the label MAN appears (pins 2 and 3).
4. This allows momentary-contact pushbutton switch SW302 to generate a strobe
signal for U302, turning the supplies on. You turn the supplies off by pressing switch
SW301.
5. You may want to troubleshoot in the low-voltage mode by plugging the high voltage
secondary plug into J303. The previous procedure describes how to do this.