i know this is an old thread, but Isaac-1's recommendation of the 2n3584 transistor just saved my bacon. I fired up my 003 a couple weeks ago and watched the oil pressure and output voltage come up per normal. after about 10 seconds, the output voltage gauge pegged to the right. not having come across this before, and since my frequency gauge was DOA from purchase, i initially thought it might be an instrumentation problem..but thought it wise to check with a multimeter before switching the house onto it. smart move - ~170v each leg to ground, about 340 volts leg-to-leg!
after finding this thread and Isaac-1's recommendation for the transistor, then finding a number of threads documenting similar high voltage output with the transistor as the cause, i ordered one up from the bay. happened to be a motorola, $6 shipped to me. got it swapped in today and BAM!, perfect output voltage again. i wouldn't have balked at paying the ~$200 for the 'modern' VR board that is being sold if i needed to...but i'll take $6 instead any day
for those concerned about doing the soldering, there is nothing to it. these are OLD circuit boards, with big fat traces and plenty of room to work. the only advice i'd give is use some thermal paste under the transistor to better conduct heat away from it to the heat sink. i used the stuff that is sold / given away for CPU coolers. a friend had some extra after buying this
http://smile.amazon.com/Thermal-The...59123808&sr=8-4&keywords=silver+thermal+paste but you only need a couple small dots (smaller than a pea) to be effective. a local computer store may even have some small packets for cheap. if someone needs some, i've got a nearly whole tube i can send - just PM me. i did have to use a razor knife to cut through the varnish that was essentially glueing the original transistor down, but once that was done, a quick prod with the soldering iron and each leg popped out easily.
ran 30 minutes unloaded to see if things were alright, than another 30 with the house on it. i've got a single zone heat pump (5 tons i'd guess) and while i get a little light dim when it kicks on, it powers the house perfectly. given the expected rebuild interval, with a little care, i expect this generator to outlive me
ahm