Yes as equill is saying (I think), the power drain will show up weaknesses in the system. So disk access during startup and use will put a strain on the Power Board. Don't add to the draw with any externals as that will only add to the problem and contribute to a catastrophic failure. I got a 512Ke on eBay that worked fine when I turned it on, but I noticed the screen jiggling. Then I made the mistake of plugging the HD20 into it and my J1 exploded in shower of sparks with a nice little burn wound on the vinyl liner.