Lincoln Electric WIRE-MATIC SVM 117-A Service Manual page 68

F-15
STATIC SCR RECTIFIER ASSEMBLY TEST (CONTINUED)
NOTE: DO NOT DISASSEMBLE THE
SCR RECTIFIER HEAT SINK ASSEM-
BLY.
6. Test for high or infinite resistance
from the anode to the cathode of
SCR 1. See Figure F.4. Use an
analog ohmmeter (Multimeter).
FIGURE F.4 - SCR 1 Test Points.
7. Test for high or infinite resistance
from the cathode to the anode of
SCR 1 by reversing the meter leads.
See Figure F.4.
a. If a high or infinite resistance is
indicated for both tests 6 and 7,
the SCR 1 is not "shorted".
b. If a low resistance is indicated in
either tests 6 or 7, the SCR is
faulty. Replace SCR Assembly.
8. Repeat Steps #7 to test SCR 2.
9. Reconnect leads X2 and X3.
10. Reconnect Plugs J3 and J6.
11. If this test did not identify the prob-
lem or to further test the SCR, go to
the Active SCR Test.
TROUBLESHOOTING & REPAIR
WIRE-MATIC 250
F-15