Troubleshooting & Repair

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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 can kill.

PC Board on or near paper, plastic or cloth which

could have a static charge. If the PC Board canʼt be

*Have an electrician install and service

installed immediately, put it back in the static-shielding

this equipment. Turn the machine

bag.

OFF before working on equipment.

• If the PC Board uses protective shorting jumpers,

Do not touch electrically hot parts.

donʼt remove them until installation is complete.

• If you return a PC Board to The Lincoln Electric

Sometimes machine failures appear to be due to PC

Company for credit, it must be in the static-shielding

Board failures.

These problems can sometimes be

bag. This will prevent further damage and allow prop-

traced to poor electrical connections. To avoid prob-

er failure analysis.

lems when troubleshooting and replacing PC Boards,

4. Test the machine to determine if the failure symp-

please use the following procedure:

tom has been corrected by the replacement PC

1. Determine to the best of your technical ability that

Board.

.......................................................................................

the PC Board is the most likely component causing

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

the failure symptom.

Board available for PC Board troubleshooting.

2. Check for loose connections at the PC Board to

NOTE: Allow the machine to heat up so that all electri-

assure that the PC Board is properly connected.

cal components can reach their operating tem-

3. If the problem persists, replace the suspect PC

perature.

Board using standard practices to avoid static elec-

5. Remove the replacement PC Board and substitute

trical damage and electrical shock. Read the warn-

it with the original PC Board to recreate the original

ing inside the static resistant bag and perform the

problem.

following procedures:

a. If the original problem does not reappear

PC Board can be damaged by

by substituting the original board, then the

static electricity.

PC Board was not the problem. Continue

• Remove your bodyʼs static charge

to look for bad connections in the control

before opening the static-shielding

wiring harness, junction blocks, and termi-

ATTENTION

bag.

Wear an anti-static wrist

nal strips.

strap. For safety, use a 1 Meg ohm

b. If the original problem is recreated by the

Static-Sensitive

resistive cord connected to a

substitution of the original board, then the

Devices

grounded part of the equipment

PC Board was the problem. Reinstall the

Handle only at

frame.

replacement PC Board and test the

Static-Safe

• If you donʼt have a wrist strap,

machine.

Workstations

touch

an unpainted, grounded,

6. Always indicate that this procedure was followed

part of the equipment frame. Keep

when warranty reports are to be submitted.

touching the frame to prevent stat-

NOTE: Following this procedure and writing on the

ic build-up. Be sure not to touch

warranty

report,

“INSTALLED

AND

any electrically live parts at the

SWITCHED PC BOARDS TO VERIFY PROB-

same time.

LEM,” will help avoid denial of legitimate PC

• Tools which come in contact with the PC Board must

Board warranty claims.

be either conductive, anti-static or static-disipative.

PRECISION TIG 275

Lincoln Electric SVM162-B service manual Troubleshooting & Repair

Models: SVM162-B