I have found trying to use a bus powered FireWire hard drive (an owc mercury on the go) to be a bit frustrating. If I try to use the drive connected directly to the Mac it can fail to be seen by the Mac and OS X. If I use a bus powered belkin fw400 hub it works but can fail to be seen by the Mac and OS X if I leave it powered on or connected for a while with the Mac mini powered off but plugged in. Is there a particular capacitor that is used by the FireWire port that I can check? Should I just replace the 3 electrolytic capacitors? I wish to use more peripherals like a Canopus ADVC and other devices that just work better over FireWire but I want a stable port. Should I just keep using the belkin FireWire hub and recap it instead of worrying about the port on the Mac? I do plan to get an external power brick for the belkin as it was sold without one.