Lincoln Electric IDEALARC SP-255 Service Manual page 72

F-19
STATIC SCR RECTIFIER ASSEMBLY TEST
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 ana-
log 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 problem
or to further test the SCR, go to the
Active SCR Test.
TROUBLESHOOTING & REPAIR
IDEALARC ® SP-255
F-19