Lincoln Electric IDEALARC SP-250 Service Manual page 77

F-30
WIRE DRIVE MOTOR AND TACHOMETER FEEDBACK TEST
FIGURE F.10B - Plug J6 Location on G1992 PC Control Board (Code 9402 only.)
NOTE: Plugs J5 and J6 are on the inboard non-component side of the Control
Board.
4. Test for 2-25 VDC between lead
#539 (positive) and lead #541 (neg-
ative) to determine if the correct
armature voltage is being supplied.
See Figure F.10A or F.10B.
a. Insert probes in to the Molex pin
5. Pull the gun trigger.
6. Read meter.
from 2 - 25 VDC.
depending on wire feed speed.
a. If voltage to the wire drive motor
TROUBLESHOOTING & REPAIR
J8
#206B
(4J6)
J9
#541
(6J6)
cavities.
Normal DC volts is
VDC varies
armature is zero, check the
wires between Plug J5 (J6 on
Code 9402) and the wire drive
motor.
IDEALARC SP-250
J7
J4
#515B
(1J6)
#555
(2J6)
J6
#539
(3J6)
b. If the wires are okay and voltage
to the drive motor armature is
zero, the Control Board may be
faulty. Replace.
c. If the correct DC armature volt-
age is present at the wire drive
motor, the motor or motor brush-
es may be faulty. Test and/or
replace.
d. If the motor is running at high
speed and the armature voltage
is high and uncontrollable, pro-
ceed with the tachometer test.
F-30
J2
J5
J3