Troubleshooting - Miller S-74S Owner's Manual

7-3. Troubleshooting

Trouble
Wire feeds, shielding gas flows, but
electrode wire is not energized.
Wire feeder is on, display does not light
up, motor does not run, gas valve and
welding power source contactor do not
pull in.
Electrode wire feeding stops or feeds
erratically during welding.
Motor runs slowly.
Wire feeder power is on, displays light
up, but unit is inoperative.
Notes
OM-1500-10 Page 24
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Check cable connections. Check cables for continuity, and repair or replace cables if necessary (see
Section 5-2).
Check and reset circuit breaker at welding power source.
Check gun trigger connection. See gun Owner's Manual.
Check gun trigger. See gun Owner's Manual.
Readjust hub tension and drive roll pressure (see Section 5-5).
Change to correct size drive roll (see 5-5).
Clean or replace dirty or worn drive roll.
Incorrect size or worn wire guides.
Replace contact tip or liner. See gun Owner's Manual.
Remove weld spatter or foreign matter from around nozzle opening.
Have Factory Authorized Service Agency check drive motor or motor control board PC1.
Check for correct input voltage.
Check welding gun trigger leads for continuity, and repair leads or replace gun.
Disconnect power before troubleshooting.
Remedy