its not the 7812 its the irf740 that looks burnt. i see spindle speed drive controllers on amazon prime for $16. can i use that in place of the PW3618? http://www.amazon.com/RioRand-Driver-Controller-Spindle-Governor/dp/B00HUQY9HC/ref=sr_1_1?ie=UTF8&qid=1459738005&sr=8-1&keywords=spindle+speed+controller