Hey guys, Could shunts run out in the long run?! I took my machine to a welding repair shop, for a tune up! And out of the blue, they told me that my shunts were bad!...........I took it to an experienced 'ol man, and he max out my 250 at 350 amps! He told me those guys were just trying to steal my money!! My question is if shunts could run/wear out?!