Live torch and stuck/broken gas solenoid Clark mig230tec

[Riverside]

I was welding away at the weekend and turned machine off while I tidied garage floor. When I turned machine back on I heard a thump (I presume from a solenoid). When I went to start welding the wire was live and the gas was working although I had not pulled the trigger. The wire feed would not go until I pulled the trigger.
Any thoughts on what the problem is and how expensive to fix

 

[rtbcomp]

Welcome to the firum.

The manual is here is you haven't got one http://www.clarkeservice.co.uk/manuals/mig_welders/mig195_230te.pdf The circuit is right at the end of the document.

I'm guessing the thump comes from K1 which will be a contactor or large relay. I'm also guessing Y1 is the gas valve, so it's looking like a fault on the PCB, probably a shorted transistor or smaller relay causing K1 & Y1 to operate when the unit is powered up.

Any chance of a photo of the PCB?