Lincoln Electric IM476 LN-742H Wire Feeder - Manual (Page 40)

E-7 TROUBLESHOOTING E-7
LN-742 & LN-742H
Observe all Safety Guidelines detailed throughout this manual
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your
Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
CAUTION
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
The welding arc is variable or
“ hunting ” .
Poor arc striking with sticking or
“ blast-offs ” . The weld bead may be
ropy and narrow.
1. Check the welding cables for
loose or faulty connections.
2. Make sure the wire feed speed,
voltage, polarity and shielding
gas are correct for the process
being used.
3. Check for mechanical restric-
tions in the wire feed path.
4. Make sure the welding power
source is functioning properly.
1. Make sure the wire feed speed,
voltage, polarity and shielding
gas are correct for the process
being used.
2. Make sure the welding power
source is functioning properly.
3. Make certain the gas solenoid is
operating properly and the gas
flow rate is correct for the pro-
cedure.
4. The welding gun may be faulty.
Check for gas leaks or replace
gun.
If all recommended possible areas of
misadjustment have been checked
and the problem persists, Contact
your local Lincoln Authorized
Field Service Facility.