Miller Electric SS-74S12 - Manual (Page 25)

OM-1500−11 Page 21
6-3. Troubleshooting
Y Disconnect power before troubleshooting
Trouble Remedy
Wire feeds, shielding gas flows, but
electrode wire is not energized.
Check interconnecting cord connections. If secure, check cord for continuity and repair or replace
(see Sections 4-5 and 4-6).
Wire feeder is on, display does not
light up, motor does not run, gas valve
and welding power source contactor do
not pull in.
Check and reset circuit breaker at welding power source.
Electrode wire feeding stops or feeds
erratically during welding
Check gun trigger connection. See gun Owner’s Manual.
erratically during welding.
Check gun trigger. See gun Owner’s Manual.
Readjust hub tension and drive roll pressure (see Section 4-11).
Change to correct size drive roll (see Table 8-1).
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.
Motor runs slowly. Check for correct input voltage.
Wire feeder power is on, displays light
up, unit jogs and purges but will not
trigger.
Check welding gun trigger leads for continuity, and repair leads or replace gun.