Lincoln Ranger 305D - blown electrical?

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I'm a bit new to engine driven welders and electrical welding in general.  I recently acquired a Lincoln Ranger 305 D with about 1200 hrs on it and it has worked well so far.I had about a 2 HP 120VAC air compressor connected to one leg of the welder's generator output in order to do some gouging  for cutting pipe fence.  I was using about 280 amps on the gouging rod and noticed my air had quit.  At this time I noticed that the digital display was out but the welder was still producing an arc.Long story short - prob overloaded it with combined weld / generator output1) no power from either leg of the 120VAC plug on the welder2) red digital display on the front which displays amps is off3) welder runs full speed all the time as if "auto-idle" switch is off4) breakers on the device do not appear tripped5) still puts out welder amps (unsure if amps knob works - forgot to check)The compressor I was using sometimes bogs down and trips a 15 amp breaker in the shop.  May have done the same thing on the welder.  I'm not sure that this welder can deliver near its maximum amps and power a compressor as well.Any ideas on a) how to troubleshoot the welder - is there a hidden breaker or fuse somewhere?b) how to prevent overload in the future.   I'm think about putting a 240 to 120 transformer before the compressor and putting 240V into the transformer in order to load the welder more evenly vs getting a separate engine driven compressor or just running the compressor, turning it off and using the stored air, then gouging - don't really do a whole lot of it.Thanks for reading.DJ
Reply:Update -- now not getting any AC power or spark from the unit. Suggestions on beginning to troubleshoot?
Reply:On inspection of the inside of the unit - LOTS of dirt on all electrical surfaces - probably not a good situation.I see a module that seems to be perhaps a rectifier unit with some large capacitors and what may be some large diodes.One of the caps seems to be chewed up on the top.  Those chewed up areas are indeed holes, by the way.  Not a good sign.  Here's a picIn my experience that would be a bad cap, but it doesn't otherwise look burned.  Next step - put a multimeter on some of the inputs to the rectifier unit and look for voltage.
Reply:Sorry,  cap is not bad.  The chewed up top is from where it hits the generator from time to time.  Trying to get the front panel off - lots of wires, not so easy.Welding repair shop says its probably either the stator or the chopper.  If no AC power either, would seem to be the stator.  Will check the continuity on the stator.Last edited by dejswa; 02-01-2010 at 10:50 AM.
Reply:Likely you control bridge has blown or corroded, sits under and to the right of the chopper. Unlikely to be the chopper as you would still have a front display and auto idle. May also be a stuck brush. Thats the usual faults
Reply:Solved the problem.By the way, I typed 'stator' above, meant 'rotor'.The rotor resistance checked out to 50 ohms, confirming that the brushes and stator were intact.  After I put the wires back onto the rotor, everything worked.  I noticed that the wires were extremely loose where the connectors slipped onto each other.  I made them tighter with some pliers.  It went out one more time while welding - opened it up, really squeezed the connectors with pliers, re-connected them and so far, so good.So - bad connection of wiring terminals down by the rotor brushes, needing a bit of crimping of the connectors.Thanks everyone for reading and for the input.DJ