Gutting an iMac G4 and upgrading a Power G3

Discussion in 'PowerPC Macs' started by Sparks-Lit, Aug 16, 2008.

  1. Sparks-Lit macrumors newbie

    Aug 16, 2008
    I am currently working on a iMac G4 with a bad Logic board(Motherboard), a replacement board is out of the users price range, so I am currently gutting it to upgrade a Desktop G3. I've already added the Hard disk and the Ram, I tried switching the dvd-r(the G3 only has a dvd/cd-rw), but the G3 will not recognize the drive, I am assuming the drive is bad as well, but I didn't know if there was something i need to do to the G3 to make it work?

    Also wanted to know if it was possible to switch the processors? the G3 is only a 400 Mhz and the iMac G4 is a 800Mhz. I rarely work with apples so i'm not sure if the sockets are the same, and not even sure if they are compatible.

    I also realize that this next question is a not really possible, but I have to ask just to make sure. Is there any way to take the LCD screen of the iMac and use it as a second monitor. I realize i would propable need the logic board to do this but want to know if anyone knows of any mods.

    Is there anything else that I would be able to gut out of the iMac and use for the G4?

    Thanks Sparks-Lit.
  2. Firefly2002 macrumors 65816

    Jan 9, 2008
    The hard drive should work just fine with the G3; if it's not, there's either something wrong with it, or it needs to be reformatted (probably something wrong with it). I'd say make sure it's set to slave if there's two drives, but I'm fairly certain a B&W won't boot if there's a HDD jumper conflict, so I guess you've probably got it set right.

    As for the CPU, I'm 99% sure you can't use it.

    Unless it's a ZIF with the same pin count as the G3's CPU socket (I forget the pin count), there's no chance. However, if by some bizarre twist it's the same (I've never worked with G4 iMacs), go for it.

    However, you'd have to set the jumpers, and keep in mind the fastest you an get a Beige G3 to run (with 66 MHz system bus) is 533 MHz, or 666 MHz if you set it to an 83 MHz system bus; I believe the fastest you could get the B&W G3 to run 800 MHz, which would work.

    However, I doubt it, since the (PPC745x-based) Power Mac G4s of this era didn't have CPUs you could use in any G3 (or even earlier G4s).

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