Tweco VA 4000 Ultra-Feed - Manual (Page 42)

ULTRAFEED VA 4000
5-4 September 18, 2012
K. Wire feeds but no gas flows
1. Check to see if the gas cylinder is empty or the
valve closed.
a. Replace gas cylinder or open valve and adjust
flowmeter.
2. Check for a possible restriction in the gas line or
gas valve.
a. Remove restriction.
3. Check to see if the welding gun nozzle is plugged.
a. Clean the welding gun nozzle.
4. Check the connections on the gas valve for loose
or faulty connections.
a. Repair or replace connection.
L. Gas flows all the time or leaks
1. Make sure all connections are tight.
2. Check for foreign material inside the gas valve.
M. Wire feeds but electrode wire is not hot – there is
no arc
1. Check continuity of pins A and B of the 19 pin
power source control cable.
a. Replace the 19 pin power source control cable.
2. Make sure the power source control cable is not
damaged. A damaged power source control cable
could be activating a protection circuit on the motor
control PC board.
a. Refer to Section 4.12 Protection Of A-B Circuit.