Lincoln Electric IDEALARC CV-305 - Manual (Page 51)

STATIC OUTPUT RECTIFIER BRIDGE TEST PROCEDURE
(CONTINUED)
TROUBLESHOOTING & REPAIR F-19 F-19
IDEALARC® CV-305
6. Disconnect the D4 diode pigtail from the positive
strap. See
Figure F.5.
7. Remove the red insulating paint from the heat sink
test points. See Figure F.6.
NOTE: DO NOT DISASSEMBLE THE HEAT SINKS.
8. Test SCR1 for proper resistance. Resistance
should be high or infinite.
a. Measure the resistance from the anode to
cathode of SCR1 using an analog volt-ohm
meter (Multi meter) set at R X 1000 scale. See
Figure F.9.
b. Reverse the meter leads and measure the
resistance from the cathode to anode of
SCR1.
c. If a low resistance is measured for either test a
or b, SCR1 is faulty. Replace the SCR assem-
bly.
9. Test the resistance of SCR2 and SCR3 using the
same procedure described in Step 8.
ANODE
CATHODE
FIGURE F.6 - SCR TEST POINTS
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