hi I've got an old single phase romarc 200 amp mig welder and the wire feed isn't working , it powers up fine and the twin cooling fans work . it makes all the right noises when the torch trigger is pressed , just nothing happens at the wire feed end . is they any thing i can look for to solve this trouble ? it would be a shame to have to scrap it because the internals are a work of art stuffed full of copper . its a professional industrial unit .