Chosen Solution
Hi all, So the other day I came home to find my powermac g5 frozen with the fans going crazy. After a hard reset the machine would no longer boot any further than the grey apple (kernel) stage. After pulling the video card the machine would boot up and I could log in using remote desktop from my laptop. The machine ran that way for a couple of days until I got a new video card. When I put the new video card in the machine would not boot again.(The new card is exactly the same one as the old one)(ATI Radeon X800 XT mac edition). After pulling the card the machine still wouldn’t boot (exact same behavior as with the card) until I let it sit unplugged for 20 minutes or so. Also when it’s not booting I can see that a little red light comes on on the logic board behind the cpu’s. Anyways I’m thinking it may be a power supply issue but if any experts wanna help me out with some advice I’d be very grateful. Thanks in advance, Cory
This can be due to a Northbridge problem, or simply need a PRAM and PMU reset. The first thing to try is to reset the PMU. Refer to this picture as a reference. Hold the button in for 30 seconds. Follow this article for PMU reset instructions. SMC is Intel only with Macs. To reset the PRAM on the system, shut the system down. Once you do this, hold Command+Option+P+R and then it will reboot. Hold this for 30 seconds or until the system reboots and see what happens. If this doesn’t fix the problem, it’s the RAM, power supply or motherboard. However, some of these are due to a dead PRAM battery. Most of them seem to have bad motherboards, but it may not hurt to try new RAM and see if the problem clears up. You can try the power supply if you want, but this part is very hard to find. Here’s the guide for the PRAM Battery, the guide for the RAM and a guide for the motherboard.
