Lincoln Electric 200 service manual PC Board Troubleshooting Procedures, Electric Shock

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

F-3		TROUBLESHOOTING & REPAIR		F-3
	PC BOARD TROUBLESHOOTING PROCEDURES
	WARNING		- Remove the PC board from the static-shielding bag
			and place it directly into the equipment. Donʼt set the
	ELECTRIC SHOCK		PC board on or near paper, plastic or cloth which
	can kill.		could have a static charge. If the PC board canʼt be
•	Have	an electrician install and	installed immediately, put it back in the static-shield-
			ing bag.
	service this equipment. Turn the		- If the PC board uses protective shorting jumpers,
	input	power OFF at the fuse box
	before working on equipment. Do		donʼt remove them until installation is complete.
	not touch electrically hot parts.		- If you return a PC board to The Lincoln Electric
			Company for credit, it must be in the static-shielding
	CAUTION		bag. This will prevent further damage and allow prop-
			er failure analysis.
Sometimes machine failures appear to be due to PC			4. Test the machine to determine if the failure
board failures. These problems can sometimes be			symptom has been corrected by the
traced to poor electrical connections. To avoid prob-			replacement PC board.
lems when troubleshooting and replacing PC boards,			NOTE: It is desirable to have a spare (known good)
please use the following procedure:
1. Determine to the best of your technical ability			PC board available for PC board troubleshooting.
			NOTE: Allow the machine to heat up so that all
that the PC board is the most likely component
causing the failure symptom.			electrical components can reach their operating
2. Check for loose connections at the PC board			temperature.
			5. Remove the replacement PC board and
to assure that the PC board is properly			substitute it with the original PC board to
connected.			recreate the original problem.
3. If the problem persists, replace the suspect PC			a. If the original problem does not reappear by
board using standard practices to avoid static			substituting the original board, then the PC
electrical damage and electrical shock. Read			board was not the problem. Continue to look
the warning inside the static resistant bag and			for bad connections in the control wiring
perform the following procedures:			harness, junction blocks, and terminal strips.
PC board can be damaged by static electricity.			b. If the original problem is recreated by the
	- Remove your bodyʼs static		substitution of the original board, then the PC
	charge before opening the static-		board was the problem. Reinstall the
	shielding bag. Wear an anti-static		replacement PC board and test the machine.
	wrist strap. For safety, use a 1		6. Always indicate that this procedure was
ATTENTION	Meg ohm resistive cord connected		followed when warranty reports are to be
	to a grounded part of the		submitted.
Static-Sensitive	equipment frame.		NOTE: Following this procedure and writing on the
Devices	- If you donʼt have a wrist strap,
Handle only at	touch an un-painted, grounded,		warranty report, “INSTALLED AND SWITCHED PC
Static-Safe	part of the equipment frame. Keep		BOARDS TO VERIFY PROBLEM,” will help avoid
Workstations	touching the frame to prevent		denial of legitimate PC board warranty claims.
	static build-up. Be sure not to
	touch any electrically live parts at
	the same time.

-Tools which come in contact with the PC board must be either conductive, anti-static or static-dissipative.

PIPELINER® 200