Lincoln Electric Idealarc DC600 9773MSP Service Manual page 51

F-10
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
The weld output terminals are
always electrically "hot".
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln
Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.
IDEALARC DC-600
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. Remove any external leads
hooked to #2 and #4 on the ter-
minal strip. If the problem dis-
appears the fault is in the con-
trol cable or wire feeder.
2. If some open circuit voltage is
present (over 3VDC.) after per-
forming Step #1. then the prob-
lem is within the DC600.
CAUTION
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Check for an internal short
between leads #2 and #4.
See wiring diagram.
2. The Pilot Relay (CR4)may be
"stuck" closed.
replace.
3. Perform Firing Board test.
4. Perform Control Board test.
5. Perform the SCR Output
Bridge test.
6. The SCR Snubber(s) may be
"leaky". Check or replace.
See wiring diagram.
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