Troubleshooting Guide - Lincoln Electric LN-25 Service Manual

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Troubleshooting Guide –
components. See Wiring Diagrams for troubleshooting of specific circuits.
PROBLEMS
(SYMPTOMS)
NOTE: Many options and possible option combinations are available for the LN-25™. In many cases, it is
best to disconnect the options and test the LN-25™ in its "basic" form. In this manner, many possible faulty
circuits can be isolated and/or eliminated from the troubleshooting procedure.
Major physical or electrical damage
is evident when the box cover is
removed.
When gun trigger is pulled, there is
no wire feed.
NOTE:On codes above 10100, the
motor leads (541 & 539) are
in Control Board Connector
J4, pins 13 & 14.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely,
contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed.
Call 1-888-935-3877.
All manuals and user guides at all-guides.com
TROUBLESHOOTING AND REPAIR
See Wiring Diagrams for location of specified
POSSIBLE AREAS OF
MISADJUSTMENT(S)
FEEDING PROBLEMS
1. Contact Lincoln
Ser vice Depar tment 1-888-
935-3877.
1. Check to see if the drive rolls
are tur ning when the gun
trigger is pulled. If the drive
rolls are turning, then check for
a mechanical restriction in the
wire feed path.
2. If the drive rolls do not turn,
then check to ensure the power
source is on and an open
circuit voltage (OCV) is present
at the weld terminals.
3. Make sure the LN-25™ work
clip is connected to the work
piece or work terminal.
4. Ensure the LN-25™ polarity
switch matches the electrode
polarity.
5. Check if the jumper plug on the
control board or contactor
board (if used) is loose or
missing.
6. Make certain the power source
open circuit voltage is above 15
VDC but not more than 110
VDC.
7. Check if the gun trigger is
faulty. Repair or replace.
8. On "older" control boards,
check the 1/8 amp fuse. If
"blown", the gun may be faulty.
CAUTION
LN-25™
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
Electric
1. With the gun trigger circuit
activated and the mode switch
in the CV position, check for
the presence of 2 to 23 VDC at
leads 539 to 541. This is the
nor mal range for ar mature
voltage, which is dependent on
the wire speed setting.
2. If the normal armature voltage
is present at leads 539 to 541,
then the motor or motor
brushes may be faulty. Check
or replace.
3. If the correct armature voltage
is missing, then remove any
option plugs that may be
connected to J3 on the control
board. Install the jumper plug
into the J3 receptacle. If the
problem is solved, then the
option board may be faulty.
4. Check the wire speed control,
range switch and associated
wiring to the control board.
5. If the correct armature voltage
is still not present at leads 539
to 541, then the control board
may be faulty. Replace.
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Observe Safety Guidelines