Troubleshooting & repair, Static output rectifier bridge test (continued) – Lincoln Electric IDEALARC CV-300 User Manual
Page 55
6.
Disconnect the D4 diode pigtail from
the positive strap. See Figure F.7.
FIGURE F.7 - Procedure to disconnect
the D4 diode pigtail from the positive
strap.
7.
Remove the red insulating paint
from the heat sink test points. See
Figure F.8.
FIGURE F.8 - Heat sink test points.
NOTE: DO NOT DISASSEMBLE THE
HEAT SINKS.
8.
Test SCR1 for proper resistance.
Resistance should be high or infi-
nite.
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.
FIGURE F.9 - SCR test points.
b.
Reverse the meter leads and
measure the resistance from the
cathode to anode of SCR1. See
Figure F.9.
c.
If a low resistance is measured
for either test a or b, SCR1 is
faulty. Replace the SCR
assembly.
9.
Test the resistance of SCR2 and
SCR3 using the same procedure
described in Step 8.
STATIC OUTPUT RECTIFIER BRIDGE TEST (CONTINUED)
ANODE
CATHODE
F-16
TROUBLESHOOTING & REPAIR
F-16
IDEALARC CV-300