Pc Board Troubleshooting Procedures - Lincoln Electric IDEALARC DC-600 Operating Manual

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
Sometimes machine failures appear to be due to PC board
failures. These problems can sometimes be traced to poor
electrical connections.
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 electrical damage and
electrical shock. Read the warning inside the static
resistant bag and perform the following procedures:
P.C. Board can be damaged by static
electricity.
ATTENTION
Remove your body's static charge before
Static-Sensitive
opening the static-shielding bag. Wear an
Devices
anti-static wrist strap. For safety, use a 1 Meg
Handle only at
Static-Safe
ohm resistive cord connected to a grounded
Workstations
part of the equipment frame.
Reusable
Container
Do Not Destroy
Page 22
TROUBLESHOOTING

PC BOARD TROUBLESHOOTING PROCEDURES

To avoid problems when
Idealarc DC-600
- 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 P.C. Board must be
either conductive, anti-static or static-dissipative.
- Remove the P.C. Board from the static-shielding bag
and place it directly into the equipment. Don't set the
P.C. Board on or near paper, plastic or cloth which could
have a static charge. If the P.C. Board can't be installed
immediately, put it back in the static-shielding bag.
- If the P.C. Board uses protective shorting jumpers, don't
remove them until installation is complete.
- If you return a P.C. 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.
4. Test the machine to determine if the failure symptom has
been corrected by the replacement PC board.
Note: It is desirable to have a spare (known good) PC board
available for PC board troubleshooting.
Note: Allow the machine to heat up so that all electrical
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 terminal
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
PROBLEM," will help avoid denial of legitimate PC board warranty
claims.
IMA 607A