Greetings Jonny I've said this before and I'll say it again, I worked in the electronic industry for a very long time. I was Field Service Manager and Technical Support manage for the first PCM Digital Telephone Switch which was installed at Ridge Crest, Ca. One of the periodic maintenance procedures was "Clean The Air Filters" I've used my MAC G4 since 1999 and haven't had any Power Supply problems. I have always had those "Air Cans" and I open the box up every 6 months and blow out the accumulated dust and webs that are in the Power Supply and every where else that they gather. So Jonny if you want everything to last a long time get yourself some of the compressed air and keep the insides free of junk. Cheers Harry San Jose, Ca ----------------------------------------------------