MK Products Cobra Gold Gooseneck - Manual (Page 18)

Cobra Gold Owner's Manual - Page 13
Troubleshooting Guide
Regardless of which torch or feeder used, all M.K. Products’ push-pull guns
operate on the same principle. The slave motor in the feeder runs at a fast,
constant speed, but has very low torque. It is always trying to feed more wire
than the torch motor wants, and when the motor gets all it wants, it slows the
slave motor, preventing a bird’s nest. Because of the low torque produced by
the slave motor, a brake system is used to prevent wire overrun rather than
tension. The drag adjustment in the feeder is used simply to keep the wire
slightly taut, so it will not pull off the spool while feeding wire.
The high torque 24VDC torch motor is controlled by a solid state speed
control located in the feeder, and a pot located in the torch. The torch motor,
potentiometer, and micro switch are connected to the cabinet/control box via
a control cable and Amphenol connector. If this cable becomes damaged, a
variety of symptoms can occur, depending on which wire(s) break. To test,
check each wire for continuity and shorts.
Remember, the micro switch in the torch activates both the slave motor and
torch motor circuits in the cabinet. Therefore, if the slave motor and brake
solenoid operate, but the torch does not, look more toward the torch motor’s
24 V circuits, speed control, control cable, or the torch motor. If nothing
operates, look more toward the slave motor’s input, micro switch leads, or
micro switch.
Testing The Torch
See "W" clocked torch wiring diagram for information
about pin-outs and locations.
Motor Check
Remove the torch connector from the cabinet.
Using the torch Amphenol connector, check the resistance across pins
“A”
and “B” (motor leads). The resistance across the motor should be between 5
- 10 ohms as the potentiometer is turned.
If an open circuit or short exists, check the motor leads and motor
independently.
Testing the Potentiometer - “W” Clocked
Using the torch Amphenol connector, check the resistance across pin “D”
(wiper) and pin “C”. The resistance should vary from 0 - 5K ohms as the
potentiometer is turned.
Check the resistance across pin
“D” (wiper) and pin “G”. The resistance
should vary from 5K - 0 ohms as the potentiometer is turned.
Testing the Micro Switch
Using the torch Amphenol connector, check for
continuity across pins “E” and “F” when the
trigger is pressed.
Section E
(Cont.)
A
F
G
E
D
C
B
"W" Clocked
Amphenol Connector
Viewed from front of connector