PRECISION TIG 275

Return to Section TOC Return to Master TOC

Return to Section TOC Return to Master TOC

Return to Section TOC Return to Master TOC

 

F-12

TROUBLESHOOTING & REPAIR

 

F-12

 

Observe Safety Guidelines

 

 

 

TROUBLESHOOTING GUIDE

 

detailed in the beginning of this manual.

 

 

 

 

 

PROBLEMS

 

POSSIBLE AREAS OF

 

RECOMMENDED

 

 

 

 

 

 

(SYMPTOMS)

 

MISADJUSTMENT(S)

 

COURSE OF ACTION

 

 

 

 

TIG WELDING PROBLEMS

 

 

 

 

 

High frequency “spark” is present

1. The spark gap may be too large.

 

1. The

high voltage transformer

 

but weak.

 

Check and reset per instructions

 

(T2) may be faulty.

 

 

 

 

this manual.

 

2. Capacitor C6 may be faulty.

 

 

 

in the Maintenance Section of

 

3. The high frequency transformer

 

 

 

2. The work and/or torch cables

 

 

 

 

may be in poor condition allow-

 

(T3) may be faulty.

 

 

 

 

ing the high frequency to “leak”

 

 

 

 

 

 

 

to ground. Use good quality

 

 

 

 

 

 

 

cables, preferably those with a

 

 

 

 

 

 

 

high natural rubber content and

 

 

 

 

 

 

 

as short as possible.

 

 

 

 

 

 

 

3. If helium shielding gas is being

 

 

 

 

 

 

 

used, reduce the percentage of

 

 

 

 

 

 

 

helium.

 

 

 

 

 

 

 

4. Make sure the tungsten elec-

 

 

 

 

 

 

 

trode is the correct size for the

 

 

 

 

 

 

 

process.

 

 

 

 

 

Poor arc starting in the

DC TIG

1. The input line voltage may be

 

1. Check the J11 plug on the con-

 

mode.

 

low.

 

trol board. See Wiring Diagram.

 

 

 

2. Check the torch and work cable

 

2. Check the background resistor

 

 

 

for loose or faulty connections.

 

R7.

Normal resistance

is 20

 

 

 

 

 

ohms.

diode

 

 

 

 

 

3. Check the background

 

 

 

 

 

bridge.

 

 

 

 

 

 

 

 

 

Return to Section TOC Return to Master TOC

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 1-888-935-3877.

Page 58
Image 58
Lincoln Electric SVM162-B service manual Maintenance Section, High frequency transformer