Lincoln Electric SVM176-A service manual Perform Potentiometer Test

F-5

TROUBLESHOOTING AND REPAIR

F-5

Observe Safety Guidelines detailed in the beginning of this manual.

PROBLEMS

POSSIBLE AREAS OF

RECOMMENDED

(SYMPTOMS)

MISADJUSTMENT(S)

COURSE OF ACTION

Drive rolls turn but wire does not

FEEDING PROBLEMS (cont.)

1. Straighten gun and clean if nec-

1. Gun cable is excessively bent or

feed or feed is erratic.

is dirty.

essary. Perform Gun Test.

2. Weld wire tangled or binding in

2. Open Cannister and if neces-

wire reel enclosure.

sary cut and reload wire.

3. Worn drive rolls.

3. Reverse or replace. Refer to

4. Improper drive roll tension.

Section D.

4. Reset tension . Refer to Section

D.

Improper speed control.

1.Defective potentiometer, Control

1. Perform Potentiometer

Test,

Board or motor.

Wire Feeder

Test

and

Feed

Erratic arc action.

1. Incorrect speed or voltage set-

Head Test.

1. Check procedures.

ting.

2. Replace.

2. Worn contact tip.

3. Poor connections in weld circuit

3. Repair or replace weld cables

or weld cables too small.

Cannot obtain desired voltage.

OUTPUT PROBLEMS

1. Make sure power source is set

1. Power Source defective or set

improperly.

for remote control and CV mode.

NOTE: SAM 400 & 650 CV con-

trols will always affect the

2. Defective control cable from LN-

output voltage.

2. Check continuity of voltage con-

23P to Adapter or from Adapter

trol circuit,

leads

75,76,&77

to power source.

(A,B,&C) from feeder to power

source.

3. Defective voltage control rheo-

3. Perform Potentiometer Test.

stat.

4. See the K350 Adapter test

4. Defective K350 Adapter