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Amps Section
1. A/mA scale not working:
A. Check fuse.
B. Measure across ( A/mA) terminal and
(COM) terminal and check the following
settings:
200 = 1k
20m = 10
1. Lower or higher check R19 - R23.
2. 10A scale not working:
A. Check shunt.
Capacitance Section
1. Connect the .1 F cap to the meter and check pin
14 and pin 1 of U2 with a scope (meter set to 2N).
Pin 14 350Hz - 400Hz 5Vpp.
Pin 1 350Hz - 400Hz .14Vpp.
A. No signal at pin 14.
1. Check R40 - R43, C12, C13, and IC3.
B. No signal at pin 1 but present at pin 1.
1. Check R44, R45, VR1, D6, and D7.
Pin 8 350Hz - 400Hz .3Vpp.
C. No signal at pin 8.
1. Check R46 - R48, D8, D9, C14, and
C15.
2m = 100
200m = 1
h
Section
FE
1. Check for shorts on socket pins.
2. Measure across base (B) terminal to COM
terminal for 209k
A. Lower or higher than value; Check R49
(NPN) and R50 (PNP).
Decimal Point Section
1. Displays two decimal points.
A. Shorted resistors R7 - R9.
2. No decimal points displayed.
A. Check R7 - R9.
Diode
1. Measure voltage across V OHM and COM
terminal (set in diode mode) = 3V.
A. Low voltage, check R51, R53, and R54.
Buzzer
No Sound
Pin 1
Pin 2
Pin 3
Pin 4
Pin 5
Pin 6
Pin 7
Pin 1 of IC2 - 1.5kHz.
1.6Vpp
6V
-26-
to 231k .
U2 Voltages
Sound
–5.5
Pin 1
–5.5
Pin 2
–5.5
Pin 3
3
Pin 4
0
Pin 5
3
Pin 6
–5.5
Pin 7
–1.87
–1.87
–1.87
3
0
0
1.87
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