I have a 'Sawtooth' APG graphics model Powermac G4 desktop. A few months back I installed 1 gig Sonnet tech Processor upgrade, the computer origionally being 450mgz. Also, about two months back, I found a monitor on the side of the road that worked fine and was slightly bigger than my old one. Within the past month, however, upon starting the computer the monitor would ocasionally give me a flashing message to check the cable connection to the PC (i'm using an Emachines monitor on a Mac), and the only way to get the monitor to work is to restart the computer. I thought this to be a problem with the monitor: the connection is always fine and the computer has no history of problems anything like this. I figured it was a piece of s--- and I'd get my old one back as soon as I could.the following has been locking up on me, requiring me to restart it. If music/game/video is playing, the sound will be stuck skipping, and the cursor is locked and won't move. Then the real problem started. The computer started freezing, forcing me to restart. At first it only did this ocasionally, but then it started happening every five minutes. In addition to this, the monitor was now giving me the error message every time I turn on the computer, so now I have to restart my computer in the middle of start up every time, and restart every five minutes. After bringing it to the mac store, they determined that the problem was hard ware related by booting the machine from one of their own hard drives and still finding it freezing. But the monitor didn't give them any trouble, so I figured it was still my s---ty monitor. 2 monitors later the computer is giving me a picture once out of every twenty or so attempts, and it's still freezing. What I've done about it: Although the computer ran fine with it for 3+ months, my first suspicion was that the heatsink, the stock one for the 450mz processor, was too small for the more powerful processor. I bought a fan online that ended up being too big to fit in the case, and then I bought some thermal compound to add to the processor/heatsink connection. The thermal compound helped the freezing at first, but it's now freezing just as often as before, at least when I can get the monitor to give me a picture. In desparation I also tore off the plastic pannel on the side of the case where the primary case fan is, allowing it to blow air straight out of the machine rather than into a dead air space between the case and the plastic: this did not appear to help, though I like how much narrower it made the case heh heh. I've also brought it to the Genius bar at the Apple Store, with limited results that I mentioned above, but they couldn't help me any further because of the third party upgrades in the machine. I also ran a Ram test on it, using a OS 9 copy of Mac Test Pro that the apple store people forgot to take out of my CD Rom. That came up negative. Just to be safe, I tried pulling the ram chips and trying them in the machine one at a time: I've got 980 megs that the machine came with when I bought it used, and I encountered nothing different with any of them because the monitor didn't work often enough for me to be able to tell. So now that I have tried everything I know how to do and still have pretty much no information to go on, I'm bringing it to a third party repair shop to see if they'll do the repair work nessesary. Being a poor student film maker, this computer is pretty much all I've got as far as equiptment goes, and I need it running. Can anyone help me out at all? Is it bad ram? A broken video card? or is it really a cooling problem like I thought it was at first? Is there some sort of special dance I can do to make my computer better?

I'm having the same exact problem!!! nobody can tell me what to do...any luck so far?