miller 350 cc cv

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hi, had a 350 miller welder blow up. is this a problem with this welder or did I do something wrong. I was welding with my mig at the time and the shop was cold.
Reply:they just blow up from time to time, now if you ran a screwdriver  into the side of it, it might be your fault. The shop I maintenance, has 22 Miller 350 Mig welders, had 3 blow up last year. The cost was about $1850 to repair.
Reply:Capacitors and diodes.  Mostly diodes.  Diodes are supposed to only allow electricity to go one way, but they can age.  Transistors are basically diodes BTW.If one goes, you can basically get 230 AC going to the wrong part of a circuit board.Moisture + freeze thaw cycles can hurt.Vibration - like sitting on a trailer with no suspension - can hurt.Finally, there's heat.If Moisture and/or vibration loosened up the connection to a heat sink, the diodes/capacitors could overheat (mostly diodes) and melt.I seem to recall some Dynasty 200s needed a check of the torque on the nuts holding down diodes.BTW, if a diode goes, its possible electricity will flow the wrong way through a capacitor and if the gell/wax inside them gets hot enough to vaporize, the capacitor can literally explode.  If you are lucky the explosion just knocks the top off the capacitor and you replace it and the diodes.  If you are unlucky, it takes out a few traces on the circuit boards.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX