Lincoln Electric MAGNUM IM647-A - Manual (Page 21)

E-3 TROUBLESHOOTING E-3
MAGNUM® 400 FM DUAL PROCEDURE GUNS
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
Poor arc striking with sticking or
“blast-offs”, weld porosity, narrow
and ropy looking bead, or electrode
stubbing into plate while welding.
Tip seizes in diffuser.
a. Improper procedures or tech-
niques.
b. Improper gas shielding.
a. Tip overheating due to prolonged
or excessive high current and/or
duty cycle welding.
a. See “Gas Metal Arc Welding
Guide” (GS100).
b. Clean gas cone. Make certain
that gas diffuser is not restricted.
Make certain that gas cylinder is
not empty or turned off. Make
certain gas solenoid valve is
operating and gas flow rate is
proper.
Remove gun liner and check rub-
ber seal for any sign of deterio-
ration or damage. Be sure set
screw in brass connector is in
place and tightened against the
liner bushing.
a. Do not exceed current and duty
cycle rating of gun.
A light application of high
temperature antiseize lubricant
(such as Lincoln E2067 Graphite
Grease) may be applied to tip
threads.