my friend has a mackie onyx 1620 or 1640 soundboard i cant remember which one it is. he is running it straight to his imac with a firewire cable to record in logic studios. right now he is on his 3rd mac. they keep blowing up and apple keeps replacing them. but they cant tell him why its doing it. one guy told him it was static electricity. but i dont believe that. the last time this happen the firewire card needed to be replaced on the mackie. whats going on?