Bio_Haz
Level 1 (0 points)

Q: iMac G4 Upgrade Issue

Hello, I have recently bought a iMac G4 1.25GHZ motherboard to replace my sluggish 800MHZ motherboard. All is well, I have managed to match up very cable so far except one. It appears to be the power input into the mother board and the cable will not fit into the new board. On the old board, the port the number "J16 and on the new board, it has the number "J17". The cable has 14 slots, (7 x 2) and it will not fit in the new 16 slot port (8x2).

 

Is there an adapter I can get? Will I have to get a new power supply? Can I splice some cables and put a new plug on (How, and what)?

 

Please enlighten me on this issue. THANKS!

Posted on Sep 20, 2015 6:53 PM

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Bio_Haz

Q: iMac G4 Upgrade Issue

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  • by Allan Jones,

    Allan Jones Allan Jones Sep 21, 2015 9:57 AM in response to Bio_Haz
    Level 8 (35,321 points)
    iPad
    Sep 21, 2015 9:57 AM in response to Bio_Haz

    I've been here a long time (~15 years) and I don't think this question has come up. Usually the problem with a logic board swap is that some ports don't fit the case.

     

    It could mean that the power supplies are different physically and in their electrical specs. The 1.25Ghz 17-inch G4 iMac uses a 130W power supply; the 1.25Ghz 20-inch model has a 190W power supply. Do you know which one your replacement board came from?

     

    A new PS will probably be the safest path.

     

    As this question doesn't typically come up here, I recommend you search some of the Mac modding sites (search "mac mods") to see if there is more info there.