Lincoln Electric DC-400 manual TROUbLESHOOTING

E-4	TROUbLESHOOTING	E-4
	Observe all Safety Guidelines detailed throughout this manual

PRObLEMS

(SYMPTOMS)

POSSIbLE

CAUSE

RECOMMENDED

COURSE OF ACTION

Variable or sluggish welding arc.	1.	Poor work or electrode connec-	1.	Check and clean all connections.
		tion.
			2.	Check table in instruction manual.
	2.	Welding leads too small.
			3.	Check procedures for recom-
				mended settings.
	3.	Welding current or voltage too
		low.	4.	Check and replace if defective.
	4.	Defective main SCR bridge.	5.	Check and replace if defective.
				(If S4C or S4D actuator is found
	5.	Microswitch S4C or S4D actuator		defective, replace mode switch
		defective.		cam also.)

OUTPUT control not functioning on 1. OUTPUT CONTROL switch in		1.	Place switch in “LOCAL”.
the machine.	wrong position.
2.	Faulty OUTPUT control switch.	2.	Check and replace if found faulty.
3.	Faulty OUTPUT control poten-	3.	Check and replace if found faulty.
	tiometer.
4.	Leads or connections open in	4.	Check lead continuity and con-
	control circuit.		nections for an open and repair if
			necessary.
5.	Faulty Control PC Board.	5.	Replace. See Procedure for
			Replacing PC Boards.

OUTPUT control not functioning on 1. OUTPUT CONTROL switch in		1.	Place switch in “REMOTE”.
“REMOTE” control.	wrong position.
2.	Faulty OUTPUT CONTROL	2.	Check and replace if found faulty.
	switch.
		3.	Check and replace if found faulty.
3.	Faulty remote control potentiome-
	ter.	4.	Check all leads and connections,
			internal or remote, for continuity.
4.	Leads or connections open in		Repair if necessary.
	control circuit.
5.	Faulty Control PC Board.	5.	Replace. See Procedure for
			Replacing PC Boards.

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.

IDEALARC® DC-400