i have a 140amp starweld 1500 mig welder.
the power is there, but wen i pull trigger,
you only hear a clicking noise and the feed rollers are not turning.
does anyone know wat part i need please ?
that would be much appreciated thankyou
I recently bought a "Starweld SW1500", and thought I would post a few pictures and initial test results here. Please bear in mind that I am a beginner... but I do have my friend Matt visiting and he is an experinced welder and helped me get the settings right. The SW1500 specs...
www.mig-welding.co.uk
but no circuit diagrams or internal views.
The normal power-up setup on this type of machine is that there is a small plastic-encapsulated transformer on the control printed circuit board, supplying 12 or 24 volts AC. This is rectified and fed to a relay, also often on the PCB, when enabled by the torch trigger switch. Contacts on the relay then send AC mains power to the main welding transformer. Depending on the setting of the ( rotary ) welder output voltage switch ( "power" step switch ) - which controls tappings on the primary of the transformer - from 15 to 30 volts AC at the secondary will be rectified and then available to the tip of the welding torch. This voltage is also "tapped off" to run the wirefeed motor, via the speed control circuit on the PCB. Depending on the operating voltage of the solenoid coil, the gas valve may be run from the switched AC mains, or from the DC welding output voltage.
The PCB-mounted transformers are not very rugged, and the primaries often burn out. However, as you can hear clicking - which is probably the relay - that part of the circuit is probably OK.
The relays are small, and have a hard life switching mains into the welding transformer, so the contacts often burn. You may be able to lever the plastic case off the relay, and carefully clean the contacts. If mains power does not reach the main transformer, there will be no output to strike an arc with the MIG wire at the torch tip, and no voltage to run the wirefeed motor either.
Another point of failure could be the rotary power step switch. Contacts inside can burn or break off. Test the welder at all four of the power settings. Check that the switch action is smooth and positive. It is not advisable to dismantle these switches - they tend to self-destruct and spray small parts all over the garage floor.