Lincoln Electric RANGER 305G EFI Service Manual page 14

LINCOLN ELECTRIC
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
The machine welds, but it will
not maintain a steady output.
The arc may suddenly become
hotter or colder.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WELD OUTPUT PROBLEMS
1. This condition may be
normal in 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 a new Lincoln electrode
and set the machine per the
Lincoln's recommendations.
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
connections at the weld output
terminals and welding cable
connections.
5. Check for adequate
connection between the work
cable and the work piece. The
work cable should be attached
to clean metal, 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.
7. The weld cables may be
coiled or wrapped around
metal reels or racks. This can
cause excessive electrical
Ranger® 305G EFI Service Manual
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. The engine may not be
maintaining correct RPM.
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
maintain 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
Wiring Diagram. Look for any
damaged conductors or faulty
connections.
4. There may be poor
connections in the control
wiring at the weld control
board or the chopper module
board. Pull each plug from the
weld control board and
thoroughly insect the terminals
in both the plugs and the PC
board receptacles. Make sure
the connections are clean and
that the pins are properly
seated in the plastic plug
housing. Check for loose or
damaged pins and faulty crimp
connections.
5. Check for damaged wiring
and poor connections in leads
13, 14, 23 and 25 between the
chopper module board and the
weld control board.
6. The output control or arc
control potentiometers may be
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