Lincoln Electric IDEALARC DC-1000 Service Manual page 64

F-30
FIGURE F.11 – LED 2 OPEN CIRCUIT VOLTAGE TEST POINTS
IF LED 2 does not light when #2 and #4 are
jumpered together.
1. Check for the presence of open circuit voltage
at the weld output terminals (27 to 75 VDC in
constant voltage mode, 75 VDC in constant cur-
rent mode).
a. If open circuit voltage IS present at the out-
put terminals, then check for open circuit
voltage from lead #222 (-) plug J1 to lead
#215 (+) plug J2 on the Control Board See
Figure F.11.
b. If open circuit voltage is NOT present at the
Control Board, then check leads #222 and
#215 and associated wiring for loose or
faulty connections. See Wiring Diagram.
Remove main supply power to the
DC-1000.
2. Test for continuity (zero ohms) from the output
shunt to lead #215 at plug J2 on the Control
Board. See Wiring Diagram and Figure F.11.
TROUBLESHOOTING AND REPAIR
CONTROL BOARD TEST (continued)
IDEALARC
3. Test for continuity (zero ohms) from the nega-
tive output terminal to lead #222 at plug J1 on
the Control Board. See Wiring Diagram.
4. If the previous tests do not reveal the problem
then the Control Board may be faulty. Replace.
5. If open circuit voltage is NOT measured at the
weld output terminals, then check the Output
Choke and associated heavy current carrying
leads for loose or faulty connections.
• Perform the Main Transformer Test.
• Perform the Firing Board Test.
• Perform the Static and Active SCR Tests.
If the previous tests do not reveal the problem then
the Control Board may be faulty. Replace.
® DC-1000
F-30