The quad core g5 has always been my dream computer and I finally got one from ebay! But I'm having an issue where when I turn it on, it works wonderfully for about 10 seconds to 1 minute, but then whatever's on the screen just freezes and the fans slowly get louder and louder It arrived with no HD, but I bought a mercury 3G SSD. I stuck it in this morning and booted to the CD drive (a leopard install disk from another mac). It worked perfectly this first time I booted it, and I even formatted the SSD in disk utilities on the install CD. I didn't go through with the install though because it said Mac OS wasn't compatible with the machine but that's because it's just the disk from another mac. I powered it off and went to work. When I got home I made a USB stick with bootable leopard and booted the g5 into open firmware. This is the first time it locked up and the fans went full blast. I unplugged the USB stick and tried open firmware again, but still full blast. I removed the SSD I stuck in earlier and tried again, but nope, still locked up & full blast. I then tried booting from targeted disk with my powerbook but the g5 froze on the boot menu thing that shows up when you hold alt/option (but that same boot menu worked without freezing earlier in the morning!). I googled the problem and reset the SMU. The first time I booted it after that, it booted to the leopard CD no problem! But then I tried again booting into the boot options menu with alt/option and it froze. I tried two more times to boot from the CD and it also froze each time. The weird thing is, it chimes every time I boot it, no matter if it's going to freeze or if it's going to work. Also, when it freezes booting to the leopard CD, sometimes it freezes on just a grey screen before the CD drive revs up, sometimes it freezes after the CD drive starts going, and the apple logo shows up. I don't know a whole lot about Powermacs, and I knew buying this from ebay was a long shot since it's quite old, but honestly I am DEVASTATED right now! I bought an SSD, a quadro, and 8GB of ram for this (I haven't installed any of that btw) but I'm not sure if my machine even works now or not edit: forgot to mention that when it arrived, the video card was slightly loose in the slot (it was missing its screw). The card and the slot look perfectly fine, but I wonder if there's a way I can rule out the video card even though I only have 1 (the quadro I ordered wont be here for a month or so) update 1: when it crashes, the red lights which light up are 2 and 7: "overtemp" and "checkstop"