tiredbytech

Q: g4 on-button not turning on computer

Due to my toddler playing with it, the on-button for my Power Mac G4 isn't working.

The computer is otherwise fine and I had it running [ using sleep] for 3 months, button protected, until he got

curious about the mains plug and switched the computer off.

Are there other ways to turn on the computer other than the button?

powermac g4, Mac OS X (10.3.9)

Posted on Aug 14, 2014 6:41 AM

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Q: g4 on-button not turning on computer

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  • by Allan Jones,

    Allan Jones Allan Jones Aug 14, 2014 9:04 AM in response to tiredbytech
    Level 8 (35,151 points)
    iPad
    Aug 14, 2014 9:04 AM in response to tiredbytech

    Try pressing the lower right segment of the button, the the lower left. Sometimes either a manufactiring defect or a buildup of crud can make the button sensitive to where you push.

     

    An old Mac tech once told be that an old Mac USB keyboard as shipped with the first iMacs can override the front panel button. The keyboard, Apple model M2452, has a power-on button like teh older Apple ADB keyboards and that can get around the problem. The M2452 is teh only one that has the required power button.

     

    That failing, you'd need to replace the front panel board:

     

    http://www.powerbookmedic.com/Power-Mac-G4-Front-Panel-Board-p-24895.html

     

    Note that instruction are available from a link on that page, but you need to fully identify your G4 variant--there are quite a few--before ordering.

  • by tiredbytech,

    tiredbytech tiredbytech Aug 14, 2014 1:31 PM in response to Allan Jones
    Level 1 (0 points)
    Aug 14, 2014 1:31 PM in response to Allan Jones

    Thanks.

    Tried button as suggested but no change. Spare part unavailable from quoted supplier sadly.

    Might look for the key board...or buy a new mac which I've been talking about for 2 years!!

  • by tiredbytech,

    tiredbytech tiredbytech Aug 17, 2014 6:32 AM in response to tiredbytech
    Level 1 (0 points)
    Aug 17, 2014 6:32 AM in response to tiredbytech

    A previous post talked about turning the computer on from a switch on the motherboard.

    Does any one know about this and where the switch is located?

    thanks.

  • by Allan Jones,

    Allan Jones Allan Jones Aug 17, 2014 7:11 AM in response to tiredbytech
    Level 8 (35,151 points)
    iPad
    Aug 17, 2014 7:11 AM in response to tiredbytech

    At this point we really need to know which Powermac you have. There were quite a few with different specs and logic boards. This site may help:

     

    http://www.everymac.com/systems/apple/powermac_g4/index-powermac-g4.html

     

    Somewhere on the back of your computer is a label with a UPC code. The "M" number should be on the same label. On some models the information is painted on.

  • by tiredbytech,Helpful

    tiredbytech tiredbytech Aug 18, 2014 6:54 AM in response to Allan Jones
    Level 1 (0 points)
    Aug 18, 2014 6:54 AM in response to Allan Jones

    I think it's M5183, but this is a guess from looking at a spare parts co.[reply post above] and relating this to my mac which is year 2000 and 400 gHz.

    I've looked closely at the inside and outside of the mac and can't find meaningful numbers.

    Will look again and thanks for the website. I have a friend who's cleverer than I - he is the one who'll approach a m-board.

    Will post another number or confirmation of above number if I can find anything.

  • by tiredbytech,

    tiredbytech tiredbytech Aug 18, 2014 7:12 AM in response to tiredbytech
    Level 1 (0 points)
    Aug 18, 2014 7:12 AM in response to tiredbytech

    Yes, found it!!

    M5183 as above.

    If I can switch on via the M-board, I can keep it running as before.

  • by Allan Jones,

    Allan Jones Allan Jones Aug 18, 2014 8:11 AM in response to tiredbytech
    Level 8 (35,151 points)
    iPad
    Aug 18, 2014 8:11 AM in response to tiredbytech

    Perfect! That's quite a bit earlier than the G4s in my ken, so give me a chance to research it.

  • by BDAqua,

    BDAqua BDAqua Aug 18, 2014 10:20 AM in response to tiredbytech
    Level 10 (123,670 points)
    Aug 18, 2014 10:20 AM in response to tiredbytech

    Might be time to replace the PRAM Battery, 4 years is close to their lifespan, far less if ever without AC power, & can cause strange startup problems...

     

    http://eshop.macsales.com/item/Newer%20Technology/BAA36VPRAM/ 

  • by tiredbytech,

    tiredbytech tiredbytech Aug 18, 2014 11:44 AM in response to BDAqua
    Level 1 (0 points)
    Aug 18, 2014 11:44 AM in response to BDAqua

    Yes, I did replace it but it made no difference.

     

    This problem has been going on for a year, but twice, after the mac was pronounced terminally disfunctional, my children poked the button for the

    umpteenth time and miraculously the computer started up again!!

    In that time I backed up everything onto an ext. HD , and taped a plastic box over the button,

    leaving the mac on 'sleep'. Should have taped over the mains switch too!

     

    Many thanks for the help and interest. I'm very fond of this computer, which I got 2nd hand in 2002 and which has been a rock ever since, only failing

    now because of the speed and size of the world around it.

  • by BDAqua,

    BDAqua BDAqua Aug 18, 2014 2:15 PM in response to tiredbytech
    Level 10 (123,670 points)
    Aug 18, 2014 2:15 PM in response to tiredbytech

    It sounds a bit like the bad Capacitors in the PSU thing... disconnect all peripherals, power cord, & remove PRAM battery, let sit overnight, plug everything back in & try starting it again after a PMU reset...

     

    How to reset the SMU/PMU on a Power Mac Earlier G3, G4, G5 models...

     

    http://support.apple.com/kb/HT1939

  • by a brody,

    a brody a brody Aug 19, 2014 3:43 AM in response to tiredbytech
    Level 9 (66,875 points)
    Classic Mac OS
    Aug 19, 2014 3:43 AM in response to tiredbytech

    If you can find an old keyboard for the iMac G3, I think it had the on/off switch that would work with your G4.   Also Keyspan if I remember offered a special plug in device that acted as an on/off switch.   If you can't turn it on after adding the new PRAM battery. sometimes very gently hitting the CUDA switch on the logicboard helps.  This is also on BDAqua's HT1939 link.