The machine welds, but it will not
maintain a steady output. The arc
may suddenly get hotter or colder.
1. Thisconditionmaybenormalin
the Downhill Pipe Mode. The
Downhill Pipe Mode allows the
arc current to increase and
decrease slightly as the arc
length changes.
2. Check that the electrode used
is of good quality, dry,and free
of contamination. Try using
some new Lincoln electrode,
andsetting the machine per the
Lincolnʼs recommendations for
that product.
3. If shielding gas is used, check
that the correct gas is being
used, and that the gas flow is
set correctly. Check the gas
system for damaged, pinched
or leaking hoses.
4. Check for loose or faulty con-
nections at the weld output ter-
minals and welding cable con-
nections.
5. Check for adequate connection
betweentheworkcableandthe
work piece. The work cable
should be attached to clean
meta, as close to the weld area
as practical. The weld clamp
must be in good condition and
have adequate spring tension.
6. The weld cables may be too
long, and/or too small, causing
excessive voltage drop
between the machine and the
arc.
1. The engine may not be main-
taining correct RPM. Perform
the Engine Throttle
Adjustment Test. Make sure
the engine has an adequate
supply of clean, fresh fuel.
Check the fuel and air filters,
replace if necessary.
2. If the engine still fails to main-
tain correct RPM, the engine
will need to be serviced.
3. Check the internal cables and
leads that connect the weld
winding of the stator, chopper
module, shunt, choke and the
output terminals. See the
wiring diagram. Look for any
damaged conductors or faulty
connections.
4. Theremaybepoor connections
in the control wiring at the weld
controlPC board or the chopper
board. Pull each plug from the
weldcontrolPCboardandthor-
oughly insect the terminals in
both the plugs and the PC
board receptacles. Make sure
the connections are clean and
that the pins are properly seat-
ed in the plastic plug housing.
Check for loose or damaged
pins and faulty crimp connec-
tions.
5. Check for damaged wiring and
poor connections in leads 13,
14, 23, and 25 between the
chopper module and the weld
control PC board.
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TROUBLESHOOTING & REPAIR
F-8 F-8
RANGER 305D
TROUBLESHOOTING GUIDE Observe Safety Guidelines
detailed in the beginning of this manual.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely,
contactthe Lincoln ElectricService Departmentfor electricaltroubleshooting assistancebefore you proceed. Call
1-888-935-3877.
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENT(S)
RECOMMENDED
COURSE OF ACTION
WELD OUTPUT PROBLEMS
CAUTION