G4 800 Dead except for power light

Posted:
in Genius Bar edited January 2014
Hi all. I went to power up my G4 800 today only to discover that the only thing that happens when I press the "power on" button is that the power light comes on, but only for as long as I hold it. The machine will not boot, or even do anything other than light the light until I take my finger off. I think I heard about one of the G4's out at the studio doing this once, and it turned out it was something that apparently happens to a certain model of G4 towers when they are allowed to sleep for a long time (this one could be nicknamed "Rip Van Winkle" since I don't use it so often).



Any ideas about where to start?

Comments

  • Reply 1 of 5
    My educated guess. Power Supply.
  • Reply 2 of 5
    slugheadslughead Posts: 1,169member
    Cuda switch.



    Open it up, find a little tiny button on the mainboard and hold it for 1 minute.



    Works every time when my dual 800 acted up.



    If you can't find it, unplug the battery.
  • Reply 3 of 5
    Thanks for the reply! Somebody over at unicornation clued me in to this yesterday, and it fixed the probalem. What no one has been able to answer yet is what this little switch actually is and what it's doing. Any ideas?
  • Reply 4 of 5
    slugheadslughead Posts: 1,169member
    Quote:

    Originally posted by Chris Fitzgerald

    Thanks for the reply! Somebody over at unicornation clued me in to this yesterday, and it fixed the probalem. What no one has been able to answer yet is what this little switch actually is and what it's doing. Any ideas?



    There's a tiny bit of RAM that is static no matter what happens. It holds pieces of information that are really important like whether or not to boot .



    The battery charges up this RAM every so often so the information is still stored.



    Sometimes, the RAM gets corrupted, and it needs to be reset.



    The switch cuts the power from the battery to the RAM, so the RAM's contents get "deleted". When the computer is started up again, it notices that the RAM is empty, it puts back some fresh information, and the cycle starts over again, this time with fresh settings.



    That's why unplugging the battery does the same thing.
  • Reply 5 of 5
    8)



    Excellent answer. Thanks!
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