Miller Electric S-74D Troubleshooting, Disconnect power before troubleshooting, Trouble Remedy

7-3. Troubleshooting

	Y Disconnect power before troubleshooting
Trouble	Remedy
Wire feeds, shielding gas flows, but	Check cable connections. Check cables for continuity, and repair or replace cables if necessary (see
electrode wire is not energized.	Section 5-2).
Wire feeder is on, display does not light	Check and reset circuit breaker at welding power source.
up, motor does not run, gas valve and
welding power source contactor do not
pull in.
Electrode wire feeding stops or feeds	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 5-6).
	Change to correct size drive roll (see 5-6).
	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	Check welding gun trigger leads for continuity, and repair leads or replace gun.
up, but unit is inoperative.

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