Hey guys I got a Millermatic 200 the old school white face. Had it for several years now and never had a problem. Welded some stuff up this weekend and it did fine. Went to fire it up yesterday and the wire kept burning back to the tip. I messed with it and finally just grabbed my smaller multimatic and got the job done. Today I blew the dust out of it which been needing done for awhile then got some scrap to see if maybe it would work right. Now the speed has gone crazy on it no matter where I turn it the wire is going super fast I can have it on 0 on speed and high 5 on voltage and its still fast. I'm guessing the knob went out. Where would I get a replacement? and this has to be it right. I do have some electrical experience I have got the multimeter ahold of anything past just checking the voltage going into the machine and after switch.