MK Products CobraMig 260 PS/Feeder - Manual (Page 34)

CobraMig 260 Owner's Manual - Page 28
FLOW CHART
PROBLEM AREA
CURRENT SENSOR, COBRA I MAIN BOARD, READ POSA START SECTION.
SYMPTOM
POSA START NO WORKING PROPERLY
9 9
NO
YES
PLUG IN J2
REMOVE J1 ON COBRA I MAIN BOARD.
USING OHM METER MEASURE RESISTANCE OF
CURRENT SENSOR
THE READING SHOULD BE OPEN
NO
CURRENT SENSOR IS DEFECTIVE
(CLOSED ALL THE TIME)
YES
IS READING OK ?
TO CHECK POSA START POT :
REMOVE J2 ON COBRA I MAIN BOARD, TURN ON POSA START SWITCH
USING OHM METER METER RESISTANCE AT J2-1 AND J2-2 RIBBON CABLE
READING SHOULD VARY FROM 0 TO 100K OHM
NO YES
JUMPER J1-1 AND J1-2 ON COBRA 1 MAIN BOARD
DOES TORCH MOTOR SPEED
INCREASE WHEN JUMPER IS
ADDED?
POSA START POT OR
POSA START SWITCH DEFECTIVE
USING A VOLT METER, MEASURE THE WELD VOLTAGE
AT J6-2(-) AND J6-1(+) ON COBRA I MAIN BOARD
SET POSA POT = 1/4 TURN ON
SET TORCH POT = MAXIMUM (CW)
TURN ON COBRAMIG 260
TRIGGER AND ADJUST WELD VOLTS TO APPROX 15V
COBRA I MAIN BOARD
IS DEFECTIVE
CURRENT SENSOR IS DEFECTIVE
(OPEN ALL THE TIME)
IS READING OK ?
START