TM 11-6625-1633-45
the forward and reverse resistance of either emitter or
3-14. Out-of-Circuit Transistor Tests
collector diodes of the PNP transistors, are shown in
When a transistor tester is not available, an ohmmeter
pointer moves slowly to a lower resistance value while
may be used to test the emitter and collector diode con-
forward or reverse resistance measurements are being
dition, maximum leakage (Ico), grounded emitter and
performed, the transistor is defective.
current gain do beta. Ohmmeter connections, to measure
.
PNP
transistor
Emitter-base
Collector-base
Number and
Type
Forward
Reverse
Forward
Reverse
Range
Reading
Range
Reading
Range
Reading
Range
Reading
10%
10%
10%
10%
Q1 (2N174)
RX100
7.5K
RX1
4
RX1
4
RX100
8K
Q2 (2N600)
RX10,000
10M
RX100
300
320
RX100
RX10,000
10M
Q3, Q4, Q5
RX10,000
7-15M
RX100
340
340
RX100
RX10,000
10-15M
Q6 (2N404)
Figure 3-15. Transistor diode test connection diagram.
3-18
