Lincoln Electric IDEALARC DC-655 Service Manual page 53

F-11
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
Poor arc characteristics in all
processes.
Poor arc striking with semiauto-
matic or automatic wire feeders.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
1-800-833-9353.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WELDING PROBLEMS
1. Check the three-phase input
line voltage at the machine.
The input voltage must match
the rating plate and reconnect
panel.
2. Check the welding cables for
loose or faulty connections.
3. Make sure the proper welding
procedures are being used.
(Wire feed speed, arc voltage
and wire size)
4. Make sure the negative welding
cable is connected to the cor-
rect negative output terminal.
(Low or High inductance)
1. Make sure the proper welding
procedures are being used.
(Wire feed speed, arc voltage
and wire size)
2. Check the welding cables for
loose or faulty connections.
CAUTION
IDEALARC DC-655
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Check the weld mode switch
(SW2) and associated leads for
proper operation or loose or
faulty connections.
Wiring Diagram.
2. Perform the Firing Board Test.
3. Perform the SCR Bridge Test.
4. Perform the Main Transformer
Test.
5. The control board may be
faulty. See the Control Board
LED Chart.
1. Perform the Firing Board Test.
2. Perform the SCR Bridge Test.
3. The control board may be
faulty. See the Control Board
LED Chart.
F-11
See the