Keithley 2750, Service Manual

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3-4 Routine Maintenance Model 2750 Multimeter/Switch System Service Manual
Replacing the AMPS fuse
The front panel AMPS fuse protects the Model 2750 AMPS current input from an over-
current condition. Follow the steps below to replace the AMPS fuse.
WARNING Make sure the instrument is disconnected from the power line and other
equipment before replacing the AMPS fuse.
1. Turn off the power, and disconnect the power line and test leads.
2. Using a screwdriver, rotate the fuse carrier one-quarter turn counterclockwise
(
Figure 3-2 ). Release pressure on the jack, and its internal spring will push the fuse
carrier out of the socket.
CAUTION Do not use a fuse with a higher current rating than specified or instrument
damage may occur. If the instrument repeatedly blows fuses, locate and
correct the cause of the trouble before replacing the fuse.
3. Remove the fuse, and replace it with the same type: 3A, 250V, fast-blow, Keithley
part number FU-99-1.
4. Install the new fuse by reversing the above procedure.
Figure 3-2
AMPS fuse
Rotate
Counterclockwise
MODEL 2750 MULTIMETER/SWITCH SYSTEM
INTEGRA SERIES
SLOT 1
SLOT 3
SLOT 4
SLOT 5
SLOT 2
3A, 250V
MATH OUTPUT RATIO CH AVG CONT PERIOD SENSOR OCOMP
DCV DCI ACV
ACI
Ω
2
Ω
4 FREQ TEMP
RANGE
AUTO
RANGE
EXIT ENTER DIGITS RATE
REL FILTER TRIG EX TRIG STORE RECALL
OPEN
LIMITS ON/OFF DELAY DRYCKT
SAVE SETUP
CONFIG HALT
TYPE
LSYNC
TEST
MONITOR
STEP SCAN
CH-OFF CARD
CLOSE
RS-232
GPIB
POWER
SHIFT
LOCAL
!
F
500V
PEAK
FRONT/REAR
HI
INPUT
LO
SENSE
Ω
4 WIRE
INPUT
350V
PEAK
1000V
PEAK
R
CAT I
AMPS
Model 2750