G4 MDD Freezing After Sleep

Discussion in 'PowerPC Macs' started by powerpcguy, Nov 12, 2012.

  1. powerpcguy macrumors newbie

    Oct 22, 2012
    I apologize if this has been answered before, but I recently acquired a Power Mac G4 and it is freezing after being put to sleep. I put a new PRAM battery in it (which now ensures that it keeps the time and remembers my wi-fi connection passwords), but it is now inevitably freezing about 2-3 minutes after being put to sleep. It's really frustrating! The sleep functionality and ease of use is one of Mac OS's top selling points imo, so I would really like for this to work flawlessly.

    What are my options? I've also reset the little PMU button inside the machine, so between resetting the PMU and getting a new PRAM battery, I don't know what could be causing this.... HELP! :)
  2. havokalien macrumors 6502a


    Apr 27, 2006
    Kelso, Wa
    Power supply

    Well there's that darn power supply, and oh the power supply and if I remember right the power supply. The MDD is prone to power supply issue, the same thing that kills the G4 cube. Small thin power supply and years of 28 volts waiting to be awake. Start out with freezes, then just lock ups, then forced unplugging to reboot then all out failure. Worst power supply next to the macintosh II's. enjoy the Mac while you can. No removing the video card and replacing with one that's not ADC at this point will not help.

    Good luck.
  3. powerpcguy thread starter macrumors newbie

    Oct 22, 2012
    Ugh! This does not sound good. Is it possible to replace the power supply? If so, is it relatively easy?

    Any info would be appreciated. Thanks!
  4. jbarley macrumors 68040


    Jul 1, 2006
    Vancouver Island
    This is news to me, I have 3 G4 cubes, 1 stock and 2 CPU upgraded, and I also had for some time a G4 MDD, never have I experienced a power supply problem with any of them.
    The MDD served me well until I gutted it and installed a Mac mini plus a bunch of peripherals into the MDD case.
  5. DrakkenWar macrumors 6502


    Nov 7, 2010
    San Antonio,Texas
    Could be a long shot...

    It has been awhile since I have owned a MDD. A few things I would try:

    1. Reset all your ram. (G4's and 5's are FINKY critters when it comes to ram).

    2. If you have another hard drive around, give it an install and see if that changes anything.

    I do agree, the PS could be the first culprit, but it is not the only possibility.
  6. wobegong Guest

    May 29, 2012
    If it's news to you then maybe you should Google it, happened to mine also (MDD 1.42 Dual), didn't happen to every machine obviously but as you will see it was a well known fault - PSU issues plagued Apple all through the mid-late PPC years for desktops, it's very well documented.
  7. seveej macrumors 6502a


    Dec 14, 2009
    Helsinki, Finland
    it's true that the MDD's are prone to PSU -related issues. Then again, this does not necessarily implicate the PSU in your case. Replacing the PSU is hard, but not impossible and spares are available at eBay (if you go that way, get a 360W unit, the 400W is a lot noisier).

    Still, as getting a new PSU is not free, I'd try to debug the sleep issue first:
    - try the things already suggested and
    - view the system log in the console. Does it note anything between going to sleep and having to start up again? (if you're not log-literate, I'm sure someone here can help)
    - do you have any FireWire or USB-devices connected? (except the apple keyboard and mouse) if so, try to cope without them for a while and see if they might be the culprit.

    Also, I've heard of one case, where a dust-filled PSU was creating problems (when in sleep, the fans do not turn, but the PSU is still "working", albeit less. Thus it may continue heating even when computer sleeps if ventilation is insufficient.

  8. havokalien macrumors 6502a


    Apr 27, 2006
    Kelso, Wa
    Sleep heat

    The issue of heat is a side effect of sleep but 28 volt ADC port. The same reason the G4 cubes have issues. I'm glad to see the one cube owner has had no issues, but that is not the norm. The G4 cube was low wattage overall, same reason CPU upgrades must be low power versions and usually need VRM boards with them. One the G4 has a CPU upgrade its common to replace the video card, which removes the ADC port and the need for the 28 volts while sleeping taxing the power supply less. Just remember the cube power supply is just like an iMac, fabless, tight, enclosed with just some holes for vein tinting.

    Good. Luck with your MDD, sorry about all the cube conversation. At least it's related info though.
  9. archtopshop macrumors regular

    Dec 13, 2011
    If you have a multimeter, it is easy to check the power supply. Instructions are located here:


    Replacing an MDD power supply is relatively easy. Ifixit has detailed instructions here:


    The hardest part of replacing an MDD power supply is finding a good one for a decent price. There is a company that rebuilds them and sells them with a warranty, but I don't have the name handy. Maybe someone else can chime in with it. I think the price is around $100 US after sending in your dead power supply. That's certainly not cheap, but at least there is a warranty.

    Ebay is another route you can follow. The only problem with eBay is there is no guarantee you'll be buying a power supply that's any better than the one you already have. I know this from experience. YMMV.

    Good luck in your quest!
  10. MaxHeap macrumors member


    Mar 28, 2012
    The PSU's aren't hard at all to fix. Badcaps.net has threads regarding this with step by step instructions on replacing the caps and will walk you through any issues as long a you're trying.
  11. havokalien macrumors 6502a


    Apr 27, 2006
    Kelso, Wa
    Bad caps

    When I went to bad caps for the MDD all they lists the ATX conversion. All the other macs they list repair, but since its a slim power supply much like dell mini towers and mostly glued to me they just kinda gave up. Ill have to go take a look.
  12. 666sheep macrumors 68040


    Dec 7, 2009
    Wise advice. Especially if current HDD is old. Dying PSU gives other issues than sleep problems and OP didn't mention any. It's easy to say: "hey, it's PSU" because it was notorious part to fail in MDD. But not always. And not due to bad caps ;)

Share This Page