Lincoln Electric 7FH manual Problems

PROBLEMS

PROBLEM	POSSIBLE CAUSE	WHAT TO DO
9. Wire feed motor runs and	a. Power source is defective.	a. Disconnect input cable from
solenoid turns on but no arc		power source and place a jumper
voltage is present.		across sockets C & D of 14-
		socket receptacle at power
		source. If no arc voltage is
		present then power source is
		defective.
	b. Input cable is defective.	b. Disconnect input cable from
		power source and check
		continuity between socket C of
		8-socket plug and pin C of 14-pin
		plug of the input cable and socket
		D of 8-socket plug and pin D of
		14-pin plug of the input cable.
		Replace cable if no continuity.
	c. Control PC Board is defective.	c. Replace Control PC board. (See
		Procedure for Replacing PC
		boards).
10. Speed does not change when	a. Run-In and weld speeds are set	a. Set Run-In and weld speeds to
weld current flows.	to the same value or Run-In is	desired settings.
	set to - - -.
	b. Power source may be defective	b. Check input control cable per
	or there may be a control cable	problem 2e. If this is O.K. then
	problem with the serial	replace Control PC board. (See
	communications - see problem	Procedure for Replacing PC
	2e.	boards.)
11. Voltmeter does not function or	a. See problem 2e, also 67	a. Check continuity from brass
read properly when arc voltage	electrode sensing lead or	block on wire feed unit to pin-F
is present.	connections may be intermittent.	on input connector at control box.
		Otherwise, replace Control PC
		board. (See Procedure for
		Replacing PC Boards.)
12. Arrow keys do not change	a. This is normal as only WFS and	a. Refer to Operations Section of
WFS or Volts/Trim.	Volts/Trim knobs will adjust these	this manual.
	settings.
13. Purge key does not turn on	a. Defective keypad or Display PC	a. Check continuity between
solenoid but trigger closure	Board is defective.	sockets 5 and 1 of keypad
does.		connector when purge key is
		closed. If not, then replace
		keypad, otherwise replace
		Display PC board. (See
		Procedure for Replacing PC
		boards.)

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