Lincoln Electric IDEALARC DC-655 Service Manual page 48

F-6
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
The machine has welding output
but no control.
The machine does not have maxi-
mum output.
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)
OUTPUT PROBLEMS
1. Check the output control switch
(SW3) for proper setting.
2. If a remote control cable is
used, make certain the cable
and connections are good.
1. Check the three-phase input
lines at the DC-655. Make cer-
tain the input voltages match
the machine's rating and recon-
nect panel configuration.
2. Put the output control switch
(SW3) in the "Local" control
position. If the problem is
resolved, the remote unit or
wire feeder may be defective.
CAUTION
IDEALARC DC-655
Observe Safety Guidelines
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. The output control potentiome-
ter, output control switch (SW3)
or associated wiring may be
defective. See the Wiring
Diagram.
2. Perform the Firing Board Test.
3. Perform the SCR
Bridge Test.
4. The control board may be
faulty. See the Control Board
LED Chart.
1. The output control potentiome-
ter, output control switch (SW3)
or associated wiring may be
defective. See the Wiring
Diagram.
2. Perform the Main Transformer
Test.
3. Perform the Firing Board Test.
4. Perform the SCR Bridge Test.
5. The control board may be
faulty. See the Control Board
LED Chart.
F-6
Output