Hi Harry, As mentioned, I checked all the cables - reseated them all and tried booting with one or both of them disconnected. I also keep this machine relatively clean so there's no significant dust buildup (I use compressed air, just as you do). I don't suspect the PS because this was a sudden event, not a gradual one, and I haven't changed the configuration of the machine in any way from when it worked to when it didn't. I also don't suspect a blown capacitor because then I shouldn't get ANY boot, firmware or otherwise. In any case, I've looked and there are no obvious signs of damage. I think John's suggestion of the custom firmware for the CPU upgrade might be the best one so far... I'll give it a shot when I can find the disk, and report back as to whether it worked or not. In the meantime, I'd still love to replace this tower with a mini anyway (for noise and power reasons), in case someone has one they want to let go of. =) Thanks! --- amir On Thu, 23 Feb 2012, Harry A. Freeman wrote: > Amir, > > I understand that it is a single cable, I have a G4 AGP which I > purchased New in 1999. Not that I open the side panel a lot but it got > to the point that when I open the side panel the cable connecting the HD > (ATA) drives to the data buss would come loose. So after opening the > side panel I would always make sure that the cable was connected. I've > always had 2ea. drive installed in the drive cage and the drives are set > to "Cable Select" > > The DVD/CD drive is connected to a different buss know as the EIDE buss. > I think that the DVD/CD EIDE buss can effect the main ATA buss. But all > things possible. > > There is always the possibility that one of your Power Supply voltages > are low. The PS is a switching power supply and with your platform the > PS going bad is only remotely going to happen. > > One thing that I do at least once a year is blow the dust out of the PS > (I now use a 1.25Ghz Dual MDD) using compress air cans. You can get then > at a Staples Store, that where I usually get mine or at a Fry's. > > If you decide to blow the dust out of the PS and the rest of the > platform be sure to turn-off un-plug and let everything cool down for at > least 15 to 20 minutes. > > Cheers > > Harry