If you've worked w/ the 270's much, I'll just point out the obvious: they have mobo problems. I'd say about 20% of the 270's have had the "bubbling" capacitors, which dell has extended the warranty on. So, when you get in there, check out the capacitors on the mobo. If there are any that are looking suspicious, replace the mobo (dell should do this for free) because eventually, it will die.