New guy looking for guidance with a Spectrum 2050 plasma

admin

Greetings all, thanks for allowing me into your group.  I wound up in trade with a Spectrum 2050 that I was sure had problems.  The diode board on top had suffered an arc blast and most of the 70amp diodes were shot. Also one of the IGBT’s had let the smoke out (the one behind LG33 PV board).  I cleaned up and replaced the IGBT. The diode board took some work. I replaced all of the 70amp diodes, checked and measured all of the capacitors and resistors. I powered it up this morning and all went well, no fireworks and the fan was running, but R1 & R2 (50 ohm 22watt) resistors got hot and began putting of light smoke after about 30 seconds of being under power.  From the original damage, it looks like the firebal(arc) might have shot out from under R1.  Moth resistors measured at 50 ohms.  Any ideas of what could be the problem?  I tried to get the service manual from Miller and was told that tech manuals were not available to me for this machine.  Anyone happpen to have them for a 2050 Spectrum?  Thanks in advance and for letting me be a part of your groupMark in HoustonElectrician, fabricator, and wanna-be welder😂