Lincoln Electric VANTAGE 400 Service Manual page 120

F-72
WELD CONTROL FEEDBACK TEST (CONTINUED)
TEST PROCEDURE
1. Place the idle switch in the "HIGH IDLE" posi-
tion.
2. Place the mode switch in the "CC-STICK"
position.
3. Place the weld terminals switch in the "WELD
TERMINALS ON" position.
4. Make sure that nothing is plugged into either
Amphenol receptacle.
5. Connect the resistive load bank and the
ammeter to the weld output terminals per the
equipment manufacturer's instructions; also
connect the voltmeter probes across the weld
output terminals.
6. Start the machine and, apply a load of about
200 Amps, as shown on the external amme-
ter. If the machine will not produce 200
amps, apply as much load as you can.
7. Compare the readings shown on the external
ammeter and voltmeter to the amps and volts
displayed on the front panel of the machine.
8. If the readings shown on the front panel dis-
plays are about the same or very close to the
reading on the external meters, the feedback
is probably good, and this test is complete.
TROUBLESHOOTING & REPAIR
VANTAGE® 400
9. If the readings differ significantly, continue
with this procedure
10. Turn off the engine and release the load from
the weld terminals. (The load bank and
ammeter should remain connected, but the
load should be released.)
11. Perform the Case Cover Removal
Procedure.
12. Locate plugs P3 and P6 on the control PC
board. See figure #1. Remove the plugs and
check for dirt, corrosion, damaged, expanded,
or incorrectly positioned terminals. Repair or
replace wiring components as needed and
reconnect the plugs to the control board.
13. Restart the machine and apply a load across
the weld terminals that measures about 200
amps. If the machine will not produce 200
amps of current, apply as much load as you
can.
14. Using the voltmeter, measure and note the
DC voltage at the weld output terminals.
15. Check the voltage between leads #204S+ (P6-
1) and lead #208B- (P3-15) at the control PC
board Molex plugs. The voltage should be the
same as was measured at the weld terminals.
F-72