the past 4-5 months my 1999 g4 rev.1 450 seems to be showing her age. despite the upgrades listed below that i've done over the years, something seems to be out of whack. the noise is indeed a grinding type and my first reaction was that it was one of my two hard drives (40gig startup and 120 gig slave - both not originals). i should note that the noise happens only on the first startup of the morning when it's cold. if i restart it then no noise occurs. it happens to be located in a new/cooler room this winter fyi. i proceeded with the following. 1) assuming it might be the older 120 gig i disconnect power and data cables to it and restarted the machine. noise still there. 2) reconnected 120 and disconnect 40gig. no noise. 3) replaced 40gig. 4) started machine again and the noise is back. 5) repeated 1 and 2 above and had noise on both tries. upgrades over the years (nothing recently): radeon 8500 1.2gig sonnet upgrade 1.5gig of ram 2 new hd's ofcourse this leaves the power box or fan as key culprits. but here is the weird part. when i open my machine during the startup and listen the noise does not at all seem to be coming from either. of all places it seems to be coming from the motherboard. maybe it's an accoustical trick but i'm just not hearing it from the power or fan. any ideas? thanks.