IDEALARC DC-600
F-36
TROUBLESHOOTING & REPAIR
STATIC SCR TEST
5.
Test for high or infinite resistance
from the cathode to the anode of
SCR 1 by reversing the leads. See
Figure F.14.
a.
If a high or infinite resistance is
indicated for both tests 4 and 5,
the SCR 1 is not shorted.
b.
If a low resistance is indicated
in either strips 4 or 5, go to
Step 6.
6.
Disconnect the snubber circuit.
See wiring diagram.
7.
Retest SCR 1 with the snubber cir-
cuit disconnected.
a.
If a low resistance is still indi-
cated, SCR 1 is faulty.
Replace. If one SCR is shorted
they may all appear shorted.
The SCRs will have to be test-
ed separately by disconnecting
the secondary leads from the
bridge assembly.
b.
If a very high or infinite resis-
tance is indicated with the
snubber circuit disconnected,
replace the snubber circuit.
8.
Repeat Steps 3 to 7 for SCRs
2 - 6.
9.
Replace all Molex Plugs on the
Firing Board and Control Board.
NOTE: To further check the SCR’s
Function, use an SCR tester and
proceed to active SCR Test.
FIGURE F.14 - SCR 1 Test Points.
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