TM 9-4940-568-20
2-109
Table 2-19. Wire Feeder Welder Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. UNIT IS COMPLETELY INOPERATIVE – NOTHING FUNCTIONS (CONT).
With input power supplied to the wire feeder, measure the DC voltage across the () and (-) terminals of the
bridge rectifier (CR1). The measured voltage should be within 5 volts of the voltage on the output terminals of
the power source.
If not, replace wire feeder.
Check plug J1 on the motor control board for loose or faulty connections.
Tighten loose connections if possible or replace wire feeder.
2. WIRE FEED MOTOR OPERATES BUT WIRE DOES NOT FEED OR FEEDS
ERRATICALLY.
Incorrect voltage current and/or wire feed speed incorrect.
Correct voltage or wire speed.
Make sure all connections to the wire feeder are tight.
If all connections are tight, replace wire feeder.
Make sure feed rolls are tight.
Replace with new roll.
Check for too little or too much pressure on the feed rolls.
Adjust sping control knob on wire feeder.
Check for correct feed roll size for welding wire being used.
Replace with correct roll size.
Check to see if wire spool tension is too great.
Adjust tension on spool.
Check for restriction in welding gun and/or contact tip.
Remove restriction and clean tip.
Check for correct gun liner and contact tip sizes for welding wire being used.
Replace with correct tip size.
