ELECTRIC SHOCK can kill.
Have an electrician install and ser-
vice this equipment. Turn the
machine OFF before working on
equipment. Do not touch electrically hot parts.
Sometimes machine failures appear to be due to PC
board failures. These problems can sometimes be
traced to poor electrical connections. To avoid prob-
lems when troubleshooting and replacing PC boards,
please use the following procedure:
1. Determine to the best of your technical ability that
the PC board is the most likely component causing
the failure symptom.
2. Check for loose connections at the PC board to
assure that the PC board is properly connected.
3. If the problem persists, replace the suspect PC
board using standard practices to avoid static elec-
trical damage and electrical shock. Read the warn-
ing inside the static resistant bag and perform the
following procedures.
PC Board can be damaged by
static electricity.
•
Remove your body’s static
charge before opening the stat-
ic-shielding bag. Wear an anti-
static wrist strap. For safety,
use a 1 Meg ohm resistive cord
connected to a grounded part of
the equipment frame.
• If you don’t have a wrist strap,
touch an unpainted, grounded
part of the equipment frame.
Keep touching the frame to pre-
vent 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-dis-
sipative.
• Remove the PC Board from the static-shielding bag
and place it directly into the equpment. Don’t set
the PC Board on or near paper, plastic or cloth
which could have a static charge. If the PC Board
can’t be installed immediately, put it back in the sta-
tic-shielding bag.
• If the PC Board uses protective shorting jumpers,
don’t remove them until installation is complete.
• If you return a PC Board to The Lincoln Electric
Company for credit, it must be in the static-shield-
ing bag. This will prevent further damage and allow
proper failure analysis.
4. Test the machine to determine if the failure symp-
tom has been corrected by the replacement PC
board.
NOTE: Allow the machine to heat up so that all elec-
trical components can reach their operating
temperature.
5. Remove the replacement PC board and substitute
it with the original PC board to recreate the original
problem.
a. If the original problem does not reappear
by substituting the original board, then the
PC board was not the problem. Continue
to look for bad connections in the control
wiring harness, junction blocks, and termi-
nal strips.
b. If the original problem is recreated by the
substitution of the original board, then the
PC board was the problem. Reinstall the
replacement PC board and test the
machine.
6. Always indicate that this procedure was followed
when warranty reports are to be submitted.
NOTE: Following this procedure and writing on the
warranty report, “INSTALLED AND
SWITCHED PC BOARDS TO VERIFY PROB-
LEM,” will help avoid denial of legitimate PC
board warranty claims.
TROUBLESHOOTING & REPAIR
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PC BOARD TROUBLESHOOTING PROCEDURES AND REPLACEMENT
WARNING
ATTENTION
Static-Sensitive
Devices
Handle only at
Static-Safe
Workstations
Resuable
Container
Do Not Destroy
