Mac G5: Incompatible RAM?

[.devolve.]

So recently my G5 stopped working.... It will turn on fans, spin the HD, show the power light, etc but not startup. Most consistently it will give me 3 flashes from the status light, which the manual says means 'incompatible RAM.' So I installed 2 gigs of brand new RAM (in all of the different slots even!) and nothing changed....

Anyone have any experience with this? Everything I can find on the Apple support forums with similar symptoms remains unresolved, and I was hoping maybe someone here had dealt with this issue and could help me out.

Thanks!

[Casey Burns]

see if you can boot from the install disk that came with it that has the hardware diagnostic tool on it. you will hold down either the D or C key while booting, can't remember which. if it boots, run the diagnostic, which can take a really long time, but it should let you know if it's your logic board, HD, ram, etc.

[macthulhu]

Figure out exactly what model you have and google "rapidshare apple service diagnostic", or look on your favorite torrent site if you don't want to deal with rapidshare. You'll find lots of downloadable disk images, but you need to have the right one for your machine. Most of the places that have them also have the list of compatible machines. Burn the disk and boot from that. It's way more detailed and thorough than the one that comes with the computer. It's the software they'd run on the bench at Apple.

Assuming you got the right RAM for your machine, it sounds like a pretty serious problem. Make sure you try pressing the PMU button and zapping the PRAM on startup... sometimes that's all it takes.

[Casey Burns]

here's a really good mac troubleshooting page to bookmark.

macosxhints.com - Twenty steps to help diagnose and fix system issues

[.devolve.]

thanks for the responses.

It won't boot from any disk, so that's out. I've reset the PRAM and pressed the PMU button, tried starting in safe mode, verbose mode, firewire mode... still nothing. Guess it's time to call in the pros. I have an enclosure on the way so I can pull my HD and run off of my old laptop in the meantime.

That link does look helpful for future problems, though.