Lincoln Electric NA-5N Service Manual page 60

F-7
Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
The wire will not feed when the inch
down button is pressed. The wire
does inch up OK and feeds down
when the start button is pressed.
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 216-383-2531 or 1-800-833-9353.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENTS(S)
WIRE FEEDING PROBLEMS
1. If a DC400, Pulse Power 500 or a
CV400 power source is used a
Diode Kit must be installed in the
power source.
2. Check to see if light 7J on the
logic board is ON while the inch
down button is pressed. If it does
NOT light check the inch down
button and associated leads.
See wiring diagram.
•(For codes below 8300) If
light 7J DOES light when
the inch down button is
pressed the logic board
may be faulty.
•(For codes above 8300)
Jumper the AUTO tabs on
the voltage board and press
inch down button. If the
wire does NOT feed down
the logic board may be
faulty.
CAUTION
NA-5
RECOMMENDED
COURSE OF ACTION
1. Disconnect the white #21 lead
from the NA-5 polarity terminal
strip (TS1). See wiring diagram.
With the inch down button
pressed read the ACTUAL volts
on the NA-5 digital voltmeter.
The digital meter should read
over 19 volts and the wire should
inch down. If not, perform the
Voltage Board Transformer
Test. If the test is OK the voltage
board may be faulty. Replace.
2. If the voltage is over 19 volts
and the wire DOES inch down
with the #21 lead disconnected
reconnect the #21 lead to the
terminal strip and read the
ACTUAL volts with the inch
down button pressed. If the
voltage is less than 8 volts per-
form the #21 - #67 External
Resistance Test. If the resis-
tance test is OK the voltage
board may be faulty. Replace.
F-7