Lincoln Electric IM990 MAGNUM PRO 350 and 550 FUME GUNS - Manual (Page 26)

E-5 TROUBLESHOOTING E-5
MAGNUM™ PRO 350 and 550 FUME 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
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
Low or no shielding gas flow.
Wire feeder runs or begins feeding
wire without pulling the gun trigger.
1. Out of gas.
2. Gas supply is turned off or discon-
nected.
3. Gas supply flow regulator is
improperly set.
4. Machineʼs gas solenoid valve has
malfunctioned.
5. Blockage in gun along gas path.
6. Gun cable kinked or flattened.
7. Blockage due to excessive spatter
accumulation on gas cone or gas
diffuser.
8. Excessive gas leakage from sup-
ply.
10. Gas leakage at gun-to-feeder
connection.
1. Defective trigger, (contacts closed
or dirty).
2. Defective (closed) trigger circuit in
the welding machine.
3. Trigger lead(s) inside gun cable
are shorted together or commonly
shorted to either welding or acces-
sory switch circuits
1. Check that an adequate gas sup-
ply is available.
2. Check that all gas supply valves
are open.
3. Check that gas flow is set between
50 to 70 SCFH.
4. See machineʼs instruction manual.
5. Gently blow out debris from core
tube.
6. Attempt to straighten out cable, or
replace cable.
7. Clean or replace gas cone or gas
diffuser.
8. Find and repair all leaks.
10. Damaged o-rings: replace both
seals. Gun connector not fully
inserted into machine. (See
Maintenance Section).
1. Replace trigger. (See
Maintenance Section).
2. See machineʼs instruction manual
3. Damaged control leads along
cable; repair if possible.
Otherwise, replace gun cable.