Troubleshooting & repair, Warning – Lincoln Electric INVERTEC SVM129-B User Manual

Page 41

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ELECTRIC SHOCK can kill.

Have an electrician install and service
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 static-shielding
bag. Wear an anti-static wrist
strap. For safety, use a 1 Meg
ohm resistive cord con nected 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 prevent sta-
tic 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.

• Remove the PC Board from the static-shielding bag

and place it directly into the equipment. 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 static-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-shielding
bag. This will prevent further damage and allow prop-
er 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 electri-

cal components can reach their operating tem-
perature.

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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