KeepItSimple

Q: PowerMac G4 (FW800 model) will not turn on after a power failure

Hello my old PowerMac G4 FW800 belongs to my friend now and he had a power failure while the computer was on.

Now the mac won't start up. Any ideas like a reset switch somewhere?

Thanks!

 

It's a PowerMac G4 1.25 DP (FW800) running OS X 10.4

Posted on Feb 13, 2012 12:10 AM

Close

Q: PowerMac G4 (FW800 model) will not turn on after a power failure

  • All replies
  • Helpful answers

  • by japamac,Helpful

    japamac japamac Feb 13, 2012 1:32 AM in response to KeepItSimple
    Level 7 (24,390 points)
    Feb 13, 2012 1:32 AM in response to KeepItSimple

    First thing to try is a PMU reset.

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

     

    Scroll down and open the Power Mac G4 link for pictures.

  • by KeepItSimple,

    KeepItSimple KeepItSimple Feb 13, 2012 3:24 AM in response to japamac
    Level 1 (20 points)
    Feb 13, 2012 3:24 AM in response to japamac

    Thank you! I'll try that tomorrow.

  • by Texas Mac Man,Helpful

    Texas Mac Man Texas Mac Man Feb 13, 2012 6:27 AM in response to KeepItSimple
    Level 8 (46,611 points)
    Feb 13, 2012 6:27 AM in response to KeepItSimple

    If the power was off for a period of time, the internal PRAM battery may be weak or discharged, and will need replacement.

     

    When to Power button is pressed, does anything happen?

     

     Cheers, Tom

  • by KeepItSimple,

    KeepItSimple KeepItSimple Feb 13, 2012 10:20 AM in response to Texas Mac Man
    Level 1 (20 points)
    Feb 13, 2012 10:20 AM in response to Texas Mac Man

    The power was off for a short period. Nothing happens when I push the power button -- as if it's not plugged in.

    Where would I get a PRAM battery and is there a part number?

    Thanks!

  • by KeepItSimple,

    KeepItSimple KeepItSimple Feb 13, 2012 10:34 AM in response to japamac
    Level 1 (20 points)
    Feb 13, 2012 10:34 AM in response to japamac

    On that PMU reset page there are 4 pictures of PowerMac reset buttons.

    Which one is mine? It's a PowerMac 1.25 DP FW800 model M8840LL/A with "a 4X AGP ATI Radeon 9000 Pro graphics card with 64 MB of DDR SDRAM". So the AGP edition?

     

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

    •Digital Audio edition

    •Gigabit ethernet edition

    •AGP edition

    •PCI edition

  • by BDAqua,

    BDAqua BDAqua Feb 13, 2012 10:59 AM in response to KeepItSimple
    Level 10 (123,765 points)
    Feb 13, 2012 10:59 AM in response to KeepItSimple

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

     

    Other places like Radio Shack have them for about $20, but this link is to show you what you need.

  • by Texas Mac Man,

    Texas Mac Man Texas Mac Man Feb 13, 2012 2:51 PM in response to KeepItSimple
    Level 8 (46,611 points)
    Feb 13, 2012 2:51 PM in response to KeepItSimple

    Check this site for battery part numbers and sources. https://sites.google.com/site/macpram/mac-pram-nvram-cuda-pmu-battery-tutorial Mac PRAM, NVRAM, CUDA/PMU & Battery Tutorial

     

    Something else to try. Resetting the Logic Board

     

    Resetting the logic board can resolve many system problems. Whenever you have a

    unit that fails to power up, you should follow this procedure

    before replacing any modules.

    1 Unplug the computer.

    2 Press the Power On button on the front of the unit.

    3 Open the side access panel.

    4 Remove the battery from the logic board.

    5 Wait at least 10 minutes before replacing the battery.

    6 Make sure the battery is installed in the correct +/-

    direction.

    7 Reassemble the computer and test the unit.

     

    Note:

    This procedure resets the computer’s PRAM. Be sure to

    check the computer’s time/date and other system parameter settings

     

     Cheers, Tom

  • by japamac,

    japamac japamac Feb 13, 2012 3:05 PM in response to KeepItSimple
    Level 7 (24,390 points)
    Feb 13, 2012 3:05 PM in response to KeepItSimple

    Your PMU button is by the ATA connectors:

    http://imageshack.us/f/49/fw800logicbd4xu.jpg/

     

    It is quite possible that the power failure surged and blew a fuse inside the power supply.

    That requires opening the power supply to replace.

    It may be also that some internal componenet is burned and replacing the fuse will result in another blown fuse.

     

    Anyhow, working inside a PSU can be dangerous due to stored electricity in the capacitors so be careful with tools and fingers inside a PSU.

    Discharge of stored charge prior to opening is recommended.

     

    The PSU can be tested (without disassembly) using a voltmeter and these instructions:"

    D275729F-09DA-4FBB-96B3-BEEEB2C04619.html

  • by Texas Mac Man,

    Texas Mac Man Texas Mac Man Feb 14, 2012 6:10 AM in response to KeepItSimple
    Level 8 (46,611 points)
    Feb 14, 2012 6:10 AM in response to KeepItSimple

    Power Mac G4: Computer Does Not Power On, No Fan Movement

    http://docs.info.apple.com/article.html?artnum=95038

     

     Cheers, Tom

  • by KeepItSimple,

    KeepItSimple KeepItSimple Mar 20, 2012 8:16 AM in response to KeepItSimple
    Level 1 (20 points)
    Mar 20, 2012 8:16 AM in response to KeepItSimple

    Thanks SO much for that info about a month ago to help get my friend's G4 PowerMac FW800 powered up again. We tried the PMU reset, replacing the PRAM battery and resetting the logic board but none of that worked.

     

    He doesn't want to spend $100+ to have it diagnosed at our local Authorized Apple Warranty Repair Center and is ready to just dump it but needs the 1000s of photos off the hard drive. How can we get those files off a hard drive where the computer doesn't power up? Thanks!

  • by Michael Black,

    Michael Black Michael Black Mar 20, 2012 8:29 AM in response to KeepItSimple
    Level 7 (24,865 points)
    Mar 20, 2012 8:29 AM in response to KeepItSimple

    Assuming the drive works, just buy an external enclosure for it (make sure it has the connectors you need for the machine you will plug it into).  Then just access it like any external drive over USB, Firewire or whatever your enclosure and computer support.

     

    Just remember for that Mac, you need an enclosure for an Ultra/ATA-100 drive (that is an IDE drive, not a SATA drive)

  • by KeepItSimple,

    KeepItSimple KeepItSimple Mar 20, 2012 8:31 AM in response to Michael Black
    Level 1 (20 points)
    Mar 20, 2012 8:31 AM in response to Michael Black

    If we take the computer to an Apple Store can they salvage the files there without it costing a fortune?

  • by Michael Black,

    Michael Black Michael Black Mar 20, 2012 8:39 AM in response to KeepItSimple
    Level 7 (24,865 points)
    Mar 20, 2012 8:39 AM in response to KeepItSimple

    Honestly, it will be FAR cheaper to just buy a 3.5" IDE/ATA external enclosure, remove the drive, put it in the enclosure and use it that way.  Even a top of the line enclosure will be no more than about $50, a cheap one likely under $20 - any place like Apple is going to charge your for their people's time, which will add up to far more.

     

    You can find enclosures at www.macsales.com, tigerdirect, newegg, amazon...  It is not hard to remove the drive and put it in the enclosure.

     

    Alternatively, if you have access to another Mac with an empty drive bay (and the Mac is an onlder one, with an IDE interface so an older G4 Mac) you could put the drive in that machine and access it that way.

     

    Its your choice - you can always call a few places and get some estimates to do it all for you (just be sure to tell them this is a Mac with an older IDE/ATA drive so they will know they can handle the odler drive interface AND the fact it will he an HFS+ formatted drive - so a windows-only shop will be useless to you).  If you have an reliable computer shop nearby that knows about Apple machines, you could also ask them about actually just removing the drive and installing it in an enclosure for you - you would actually take care of copying the files and such, but just get them to help pull the drive and set it up in a suitable enclosure for you to use as an external drive (heck, offer them the G4 for parts in exchange for the service, if they sell or repair older Mac's?).