Troubleshooting

E-4	TROUBLESHOOTING	E-4

	Observe all Safety Guidelines detailed throughout this manual

PROBLEMS

(SYMPTOMS)

POSSIBLE

CAUSE

RECOMMENDED

COURSE OF ACTION

Output Problems

	7.	Incorrect tension arm pressure on	7.	Adjust the tension arm per the
		the drive rolls.		Instruction Manual.		Most elec-
				trodes feed well at a tension arm
				setting of "3".
	8.	The spindle brake is too tight.	8.	Verify the spool of wire moves
				with minimal effort.
	9.	Worn drive roll.	9.	Replace the drive rolls if worn or
				filled with dirt.

Wire feed speed consistently oper-	1.	The jumper lead for normal	1.	Properly	connect	the normal
ates at the wrong value. The speed		speed/extra torque is connected		speed/extra torque jumper.
changes when the wire feed speed		improperly.	2.	Install the proper pinion gear in
knob is adjusted.	2.	The wrong gear is installed in the		the wire drive.
		wire drive.	3.	Replace	the motor/gearbox
	3. The brushes on the motor are			assembly.
		worn.

The wire feed speed stuck at 200-	1.	The tachometer is connected	1.	Verify all of the tachometer leads
300 in/min and there is no change		improperly.		are properly connected.
when the wire feed speed knob is	2.	The tachometer has failed.	2.	Replace the motor and tachome-
adjusted.				ter assembly.

Variable or "hunting" arc.	1.	Wrong size, worn and/or melted	1. Replace the contact tip.
		contact tip.
	2.	Worn work cable or poor work	2.	Verify all work and electrode con-
		connection.		nections are tight and that the
				cables are in good condition.
				Clean/replace as necessary.
	3.	Wrong polarity.	3.	Adjust polarity to the recommend-
				ed procedure.
	4.	The gas nozzle is extended	4.	Adjust the gas nozzle and shorten
		beyond the contact tip or the wire		the strike out to 3/8 to 1/2 inches.
		stickout is too long.
	5.	Poor gas shielding on processes	5.	Check gas flow and mixture.
		requiring gas.		Remove or block sources of
				drafts.

When the trigger is pulled, the wire	The Run-In switch is “ON”		Use the set-up Push-button to turn
feeds slowly.			Run-in OFF.

Poor arc starts with sticking or	1. Improper procedures or tech-		1. See "Gas Metal Arc Welding
"blast-offs", weld porosity, narrow		niques.		Guide" (GS-100).
and ropy looking bead.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.

LN-25™ IRONWORKER

Output Problems