Lincoln Electric COMMANDER 400 SVM133-B Service Manual page 60

F-6
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
Low or no constant voltage (CV)
welding output. Constant current
(CC) and the auxiliary power are
operating normally.
The machine powers down within
seconds of power up and all lamp
indicators on the front panel are lit.
"ECL", "ECH", or "CSS" appears on
display as machine is shutting
down.
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 (WELD).
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. Make sure the wire feeder, con-
trol cable and welding cables are
connected correctly.
2. Make sure the range switch is in
the correct position.
3. Check the heavy current carry-
ing cables associated with the
CV output terminal.
Wiring Diagram.
1. Contact your
Authorized Field Service Shop.
CAUTION
Commander 400
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Perform the Range Switch
Test.
2. Check for poor connections at
J21 pins 1 & 4 at the CV daugh-
ter board. This is CVSCR gate
drive output.
welding in the general fab or
pipe taps.
See the
3. Check for poor connections
along lead #208 at the negative
CV output stud and at the J21
pin 6 molex plug at the CV
daughter board. This is CV volt-
age feedback input.
affect welding in the general fab
or pipe taps.
4. Perform the Control Board
Power Supply Test.
local Lincoln 1. Check to make sure that the
machine
Exciter Feedback Module Asbly.
2. Check for loose or faulty con-
nections or wires at the T1, T2 or
T3 capacitor connection block
and back to the capacitor bank.
On machines equipped with
L10953-1
Module Asbly check leads T1,
T2 and T3 for fault connections.
3. Check for loose or faulty con-
nections at leads 268, 269, &
270 from the exciter PC Board to
J4 pins 1, 2 & 3 on the control
board.
4. If possible check exciter wave-
forms as illustrated in the
Oscilloscope
Section.
5. If possible perform the Exciter
Voltage Feedback Test.
F-6
Will not affect
Will not
has an L10953-1
Exciter Feedback
Waveforms