MK Products Cobramatic 120VAC - Manual (Page 17)

Cobramatic ® Owner’s Manual - page 10
Section E Troubleshooting
Troubleshooting
Symptom Cause Remedy
No wire feed at torch, feeder
not operating, i.e., no slave
motor or brake solenoid.
F3 (2amp) fuse in feeder
blown. Check AC circuit. Replace
fuse.
F1 (4amp) fuse in feeder.
Check motor leads for shorts,
then replace fuse.
Micro-switch defective/not
being activated. Broken elec-
trical cable. Replace switch. Check switch
for operation. Check micro
switch wires for continuity.
Relay K2 inoperative. Check/Replace relay K2.
Loose J2, J3, P.C. board con-
nector
Check J2, J3 connectors.
Brake solenoid inoperative.
Solenoid defective. Replace solenoid.
Relay K2 inoperative.
Check for 42VAC across J4-1
and J4-2.
No wire feed at torch, feeder
operating properly.
Bad potentiometer.
Check potentiometer with
meter.
Bad torch motor. Check/Replace motor.
Broken electrical cable.
Check motor and potentiom-
eter wires for continuity.
Bad speed control/PCB. Check/Replace P.C. Board.
Wire feeds, but welding wire is
not energized.
Loose ot no cable connections. Check all power connections.
Relay K2 not sending contactor
signal.
Check/Replace realy K2.
Contactor control cable loose
or in wrong position.
Check power supply owners
manual for location and type of
contactor signal required, i.e.
closing contacts or AC.
Welding power source not
working right. Check power supply for proper
operation.
Wire feeds erratically.
Dirty or worn circuit. Blow out or replace conduit.
Incorrect pressure on drive
rolls.
Adjust pressure at torch.
Idler roll stuck in torch.
Check for lock washer under
idler roll, or replace if damaged
or worn.
Wrong size contact tip. See contact tip table.
Wire feeds one speed only.
Bad potentiometer. Check with meter.
Broken electrical cable in lead
assembly. Check potentiometer wires for
continuity or shorts.
Bad speed control Check/Replace P.C. Board.
Wire walks out of drive rolls.
Idler roll upside-down.
Place groove in idler roll
towards top.
Rear wire guide missing. Replace wire guide.