Series 3700A Switch and Control Cards Reference Manual
Section 5: Model 3721 multiplexer card
3700AS-909-01 Rev. A / Preliminary
5-7
Amps channel fuse replacement procedure
WARNING
Disconnect all external power from the equipment and the line cord before performing any
maintenance on the Series 3700A.
Make sure that the Model 3721 card is removed from the system before replacing the amps
fuse (see next figures).
CAUTION
Do not use a fuse with a higher current rating than specified or instrument damage can occur. If the
Instrument repeatedly blows fuses, locate and correct the cause of the problem before replacing the
fuse.
To replace the amps channel fuse:
1. Remove the top shield cover:
A. Unscrew the number 4-40 screw (1) as shown in the "Shield removal" figure below.
B. Slide the top cover in a direction away from the D-sub connectors, disengaging the cover from the
printed circuit board.
C. Lift the top shield cover off of the printed circuit board.
2. Set jumpers per options listed below.
3. Replace the top shield cover.
•
Slide the top cover in a direction toward the D-sub connectors, engaging the cover onto the printed
circuit board, and securing with the number 4-40 screw (1).
4. The card can now be returned to service.
Figure: Model 3721 shield removal
Figure 12: Model 3721 shield removal