TM 9-4940-568-20
2-111
Table 2-19. Wire Feeder Welder Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
6. NO WIRE FEED SPEED (WFS) CONTROL.
Check for a loose WFS control knob.
Tighten knob.
Check potentiometer (R1) and plug J1 on the motor control p.c. board for loose or faulty connections.
If no loose connection(s) are found, replace wire feeder gun.
With input power supplied to the wire feeder, measure the DC voltage from J1-4 () to J2-1 (-) while varying the
wire feed speed knob from minimum to maximum, the voltage range should be approximately 0.3 – 0.6 VDC.
If not, replace the wire feeder.
Make sure the power source output voltage is less than 140 VDC.
Adjust voltage.
7. WIRE FEEDS BUT NO GAS FLOWS.
Check to see if the gas cylinder is empty or the valve closed.
Replace cylinder or open valve.
Make sure proper gas flow rate has been set.
Adjust flow rate as needed.
Check for a possible restriction in the gas line or gas valve.
Remove restriction.
Check to see if the welding gun nozzle is plugged.
Remove restriction.
