Procedure For Testing Diodes - Komatsu WA250-6 Shop Manual

120 Testing and adjusting, Part 2

Procedure for testing diodes

Procedure for testing diodes

a Check an assembled-type diode (8 pins) and
independent diode (2 pins) in the following
manner.
a The conductive directions of the assembled-
type diode are indicated on the surface of the
diode as shown in the following figure.
a The conductive directions of the single diode is
indicated on the surface of the diode as shown
in the following figure.
WA250, 250PZ-6
1. When using digital type circuit tester
1
1) Switch the testing mode to diode range
and confirm the indicated value.
a Voltage of the battery inside is dis-
played with conventional circuit testers.
2) Put the red probe (+) of the test lead to the
anode (P) of and the black probe (–) to the
cathode (N) of diode, and confirm the indi-
cated value.
3) Determine acceptability of the diode from
the indicated value.
Indicated value remains unchanged:
q
Conduction is absent (Failure)
The indicated value changes: The
q
diode has conductivity (Normal) (See
below.)
a
a A value between 460 to 600 is indi-
cated for silicon diodes.
SEN03837-01
39
30-120