Technical data

5 Disassembly and Repair
74 U3401A User’s and Service Guide
To Replace a Current Input Fuse
Both the mA and the A current input terminals are fuse protected. The
fuse for the mA input terminal is located on the front panel (see page 15).
The fuse is a 0.63 mA, 500 V fuse (refer to Table 5- 2). If you determine
that the fuse is faulty, replace it with one of the same size and rating.
The fuse for the A current input terminal is located inside the multimeter
(see page 79) and requires partial disasembly of the multimeter. The fuse
is a 25 A, 440 V fast- acting fuse (refer to Table 5- 2). If you determine
that the fuse is faulty, replace it with one of the same size and rating.
Electrostatic Discharge (ESD) Precautions
Almost all electrical components can be damaged by electrostatic discharge
(ESD) during handling. Component damage can occur at electrostatic
discharge voltages as low as 50 volts.
The following guidelines will help prevent ESD damage when servicing the
instrument or any electronic device.
• Disassemble instruments only in a static- free work area.
• Use a conductive work area to reduce static charges.
• Use a conductive wrist strap to reduce static charge accumulation.
• Minimize handling.
• Keep replacement parts in original static- free packaging.
• Remove all plastics, foam, vinyl, paper, and other static- generating
materials from the immediate work area.
• Use only anti- static solder suckers.
Table 5 - 2 Type of current input fuse
Type of fuse Part number
0.63 mA, 500 V fuse 2110-1432
25 A, 440 V fast-acting fuse 2110-1431