My G5 Quad is about 6 years old and still is a great machine, until a couple of weeks ago, when it froze on startup. Led no. 7 burned, which means that your processor’s dead or you logic board. In my case, it was the latter. Brought it to a Mac repair shop, they couldn’t help me, but had to pay €140,- for the check they did. A bit of Googling around learned that if you heat the logic board with a hair dryer, sometimes the machine could be brought back to life. I had nothing to lose, so gave it a try. Yes, it worked…. for a couple of hours. The feared LED#7 burned, the machine froze, fans going full power. I did the hair dryer treatment again, a bit longer than before, and it powered up fine, ran for about 12 hrs, so I thought that the problem was solved. Next day same problem on startup, I gave up hope…..
A few days ago I talked to a computer repair guy and he told me that instead of using a hair dryer or heat gun, you should remove the logic board and put it in an oven, he told that I should google on “reflow”, and yes, several Youtube video’s showed brave people putting the guts of their G5 machines into grills and ovens. I gave it a shot, desperate as I was, and after 8 minutes at 190˚C (375˚F) the apples were grilled. Did it work? Until now, YES!!! I ran the AHT (Apple Hardware Test), logic board OK, no other problems. Even after rebooting a couple of times, no LED’s burning:-)
Hopefully I can work another year on it before moving to a new Mac Pro (I was actually waiting for the Sandy bridge model that expect to arrive Q1 2012), but I read that the 2nd gen Sandy Bridge processors will be far more powerful than the ones that arrive in january, so I hope the logic board was “well done”…..
Of course, when the G5 dies again, I’ll let you know.
Update: april 3rd 2012. It died (again)…….
Update: november 7th 2012: after using an iMac 2008 I bought an Mac Pro 2,8 Ghz 8 core. I didn’t wan’t to wait for the 2013 Mac Pro to come out, the iMac was too limited for me in terms of processing and connectivity, that’s why I bought the 2nd hand Mac Pro. Great machine, put in an SSD HD, very fast and a lot quieter than the G5 Quad, which is a nice thing in a recording studio:-)