Appendix A: Maintenance
Model 2651A High Power System SourceMeter® Instrument Reference Manual
A-2
2651A-901-01 Rev. A / March 2011
Figure 111: Fuse replacement
!
!
LINE RATING
100-240 VAC
50, 60 Hz
500VA MAX.
LINE FUSE
SLOWBLOW
5.0 A, 250 V
CHANNEL A
RS-232
DIGITAL I/O
LAN
IEEE-488
G
G G G
S
LO
SENSE/GUARD
S
HI
LO
HI
OUTPUT
40V, 50A MAX.
!
2
1
Perform the following steps to replace the line fuse:
1. Power off the unit and remove the line cord.
2. The fuse drawer (1) is located below the AC receptacle. A small tab is located on the top of the
fuse drawer (2). Using a thin-bladed knife or a screwdriver, pry this tab away from the AC
receptacle.
3. Slide the fuse drawer out to gain access to the fuse (the fuse drawer does not pull completely out
of the power module).
4. Snap the fuse out of the drawer and replace it with the same type (the fuse is specified in the
table below).
CAUTION
To prevent instrument damage, use only the correct fuse type (see table).
5. Push the fuse drawer back into the module.
If the power line fuse continues to blow, a circuit malfunction exists and must be corrected. Return the
unit to Keithley Instruments for repair.
Line fuse
Line voltage
Rating
Keithley Instruments
part number
100 V - 240 V
5 A, 250 V, FAST-
ACTING CARTRIDGE
FUSE, 5
×
20mm
FU-154-5
Front panel tests
There are two front panel tests: one to test the functionality of the front panel keys and one to test the
display.