1) ACV Range:
600
HV 0 0 0
200
0 0.0
2) DCA,10A Ranges:
200
μ
0 0.0
2,000
μ
0 0 0
20m
0.0 0
200m
0 0.0
10A
0.0 0
3) Ohms, Diode and h
FE
Ranges: B indicates blank.
h
FE
0 0 0
Diode “ ” “ ”
1 B B B
200
1 B B.B
200
1 B B.B
2,000
1 B B B
20k
1 B.B B
200k
1 B B.B
2,000k
1 B B B
4) DCV Range:
200m
0 0.0
2,000m
0 0 0
20
0.0 0
200
0 0.0
600
HV 0 0 0
-8-
TESTING, CALIBRATION, AND TROUBLESHOOTING
TESTING OF LCD
With no test leads connected to the meter, move the selector switch around the dial. You should obtain the following
readings. A (–) sign may also be present or blinking.
If any of these tests fail:
a) Check that the battery is good.
b) Check the values of resistors R14 - R17, R30 - R32.
c) Check the values of capacitors C1 - C6.
d) Check the PC board for solder bridges and bad solder connections.
e) Check that the slide contacts are seated correctly.
f ) Check that the LCD and zebras are seated correctly.
CALIBRATION
Refer to the METER OPERATION section for test
lead connections and measurement procedure.
A/D CONVERTER CALIBRATION
Turn the range selector switch to the 20V position
and connect the test leads to the V
Ω
mA and COM
sockets. Using another meter of known accuracy,
measure a DC voltage of less than 20 volts (such as
a 9V battery). Calibrate the kit meter by measuring
the same voltage and adjusting VR1 until the kit
meter reads the same as the accurate meter (do not
use the kit meter to measure its own battery). When
the two meters agree, the kit meter is calibrated. Turn
the knob to the OFF position and remove the voltage
source.
SHUNT WIRE CALIBRATION
To calibrate the shunt wire, you will need a 1A current
source such as a 5V power supply and a 5
Ω
, 5W
resistor. If no supply is available, it is not important to
do this test. Set the range switch to the 10A position
and connect the test leads as shown in Figure N. If
the meter reads higher than 1A, resolder the shunt
wire so that there is less wire between the 10A DC
and COM sockets.
If the meter reads low, resolder the shunt wire so that
there is more wire between the sockets.
If the calibration fails:
a) Check the PC board for solder bridges and bad
solder connections.
b) Check the value of resistors R10 - R12 and VR1.
Attach the bottom case without screws.
10A DC
V
Ω
mA
COM
Figure N
5
Ω
5 Watts
Power Supply
5VDC
–
+
123
