Troubleshooting and Repair

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F-3

PC BOARD TROUBLESHOOTING PROCEDURES

- Remove the PC board from the static-shielding bag

WARNING

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-

Sometimes machine failures appear to be due to PC

er failure analysis.

4. Test the machine to determine if the failure

board failures. These problems can sometimes be

symptom

has

been corrected

the

traced to poor electrical connections. To avoid prob-

replacement PC board.

lems when troubleshooting and replacing PC boards,

please use the following procedure:

NOTE: It is desirable to have a spare (known good)

1. Determine to the best of your technical ability

PC board available for PC board troubleshooting.

that the PC board is the most likely component

NOTE: Allow the machine to heat up so that all

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

connected.

substitute it with the original PC board to

3. If the problem persists, replace the suspect PC

recreate the original problem.

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

Meg ohm resistive cord connected

followed when warranty reports are to be

ATTENTION

to a grounded part of the

submitted.

Static-Sensitive

equipment frame.

Devices

- If you donʼt have a wrist strap,

NOTE: Following this procedure and writing on the

Handle only at

warranty report, “INSTALLED AND SWITCHED PC

Static-Safe

touch an un-painted, grounded,

BOARDS TO

VERIFY

PROBLEM,” will

help

avoid

part of the equipment frame. Keep

denial of legitimate PC board warranty claims.

Workstations

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.

VRTEX TM 360

Lincoln Electric SVM200-A Troubleshooting and Repair, PC Board Troubleshooting Procedures

Models: SVM200-A