Pc Board Troubleshooting Procedures - Lincoln Electric POWER WAVE SVM135-B Service Manual

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PC BOARD TROUBLESHOOTING PROCEDURES

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Sometimes machine failures appear to be
due to PC board failures. These problems
can sometimes be traced to poor electrical
connections. To avoid problems when trou-
bleshooting and replacing PC boards,
please use the following procedure:
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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 sus-
pect PC board using standard practices
to avoid static electrical damage and
electrical shock. Read the warning
inside the static resistant bag and per-
form the following procedures:
TROUBLESHOOTING AND REPAIR
WARNING
ELECTRIC SHOCK
can kill.
Have an electrician install
and service this equipment.
Turn the input power OFF
at the fuse box before
working on equipment. Do
not touch electrically hot
parts.
CAUTION
POWER WAVE 455/POWER FEED 10
PC board can be
damaged by static
electricity.
- Remove your body's
static charge before
ATTENTION
opening the static-
Static-Sensitive
shielding bag. Wear an
Devices
anti-static wrist strap.
Handle only at
For safety, use a 1 Meg
Static-Safe
ohm resistive cord con-
Workstations
nected to a grounded
part of the equipment
Reusable
frame.
Container
Do Not Destroy
- If you don't have a
wrist strap, touch an unpainted, grounded,
part of the equipment frame. Keep touching
the frame to prevent 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.
- 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 cannot
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 proper failure
analysis.
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