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F-11

 

F-11

TROUBLESHOOTING & REPAIR

TROUBLESHOOTING GUIDE

 

Observe Safety Guidelines

 

detailed in the beginning of this manual.

 

 

 

PROBLEMS

POSSIBLE AREAS OF

RECOMMENDED

(SYMPTOMS)

MISADJUSTMENT(S)

COURSE OF ACTION

 

 

 

 

FUNCTION PROBLEMS

 

The SET voltage is erratic or not

1. Check for loose or faulty con-

1. Remove power to the LN-9

adjustable over the entire range of

nections on leads #634, #635,

GMA and disconnect Plug J9

control. The actual voltage is also

and #636 between the voltage

from the voltage PC board.

erratic like the SET voltage.

control potentiometer (R3) and

Check the resistance of the volt-

 

the voltage PC board.

age control potentiometer (R3).

 

 

When measured from the wiper

 

 

(lead #635) to lead #634, the

 

 

resistance should vary smoothly

 

 

from 0 to 10,000 ohms when the

 

 

shaft is rotated.

 

 

2. The voltage PC board may be

 

 

faulty. Replace.

 

 

 

The field fuse (F101), located on

1. Make sure the replacement fuse

1. Perform the T1 Transformer

the power PC board, repeatedly

is a 4/10 amp slow blow type

Test.

fails.

fuse.

2. Disconnect the meter PC board.

 

 

 

 

If the problem is resolved, the

 

 

meter PC board may be faulty.

 

 

3. The power PC board may be

 

 

faulty. Replace.

 

 

 

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con- tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 216-383-2531 or 1-800-833-9353.

LN-9 GMA Wire Feeder

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Lincoln Electric SVM138-A service manual Test