bpali2001

Q: I clicked the PMU reset button twice!:(

I have the PowerMac G5  single processor single core 1.6 GHz model. It wasn't booting up. There was some power going to the 23" apple hd cinema display but it looks like not enough to drive the display. I turn the thing on. Hear the startup chime. And after that the power indicator led starts blinking. flashing one by one.

what should i do????

PowerMac, Mac OS X (10.5.8), 1.6 GHz Single Core Single Processo

Posted on Jan 31, 2015 5:16 AM

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Q: I clicked the PMU reset button twice!:(

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  • by Drew Reece,Helpful

    Drew Reece Drew Reece Jan 31, 2015 5:23 AM in response to bpali2001
    Level 5 (7,480 points)
    Notebooks
    Jan 31, 2015 5:23 AM in response to bpali2001

    Which LED is flashing?

     

    The displays white LED?

    The Mac's white power LED?

    Something else?

     

    These 'flashes' often have a pattern - you need to watch & describe it. e.g. long flash, short flash…

     

    The G5 does not power the display, it only sends data.

  • by bpali2001,

    bpali2001 bpali2001 Jan 31, 2015 5:39 AM in response to Drew Reece
    Level 1 (0 points)
    Jan 31, 2015 5:39 AM in response to Drew Reece

    the power leds (white on the displays power button + white on the g5 itself by the power button)
    i found the patterns on the internet but mine is different. short flashes. just one at a time. it looks like theres no pattern to it

  • by Drew Reece,Helpful

    Drew Reece Drew Reece Jan 31, 2015 6:12 AM in response to bpali2001
    Level 5 (7,480 points)
    Notebooks
    Jan 31, 2015 6:12 AM in response to bpali2001

    I'd power off, disconnect the display see if the Mac does the same pattern without it.

     

    Do you have remote access or any other way to see access the Mac from another machine? If you can see it appear in the shared sidebar on another Mac it indicates startup completed.

     

    Obviously try other displays if you have any suitable ones.

     

    Other things to try…

    How to Reset NVRAM on your Mac - Apple Support

    OS X: What is Safe Boot, Safe Mode? - Apple Support

    Mac OS X: How to start up in single-user or verbose mode - Apple Support

     

    If you have the grey install DVD's …

    Using Apple Hardware Test - Apple Support

     

    Also try booting the 10.5 install DVD/CD.

     

    You may be able to read the HD on another Mac assuming you have one & the correct leads…

    How to use and troubleshoot FireWire target disk mode - Apple Support

     

    I'll try to look around for LED error code info, it may be tomorrow when I get back to you, good luck in the meantime.

  • by bpali2001,

    bpali2001 bpali2001 Jan 31, 2015 7:18 AM in response to Drew Reece
    Level 1 (0 points)
    Jan 31, 2015 7:18 AM in response to Drew Reece

    tried everything. other monitor. no monitor. resetting the pmu accidentally twice. it looks like the os didn't even wants to boot up. i don't have any install dvds. so yeah I'm basically screwed.

     

    do you think its a great idea to buy a new ssd plus a hdd too? os on the sdd. pictures n stuff on the hdd.

    the ram is cool. works fine. I'm alright with 2.5 gigs

    nvidia fx 5200 is also enough for my needs. that 64mb of vram tho lol

  • by Drew Reece,

    Drew Reece Drew Reece Jan 31, 2015 9:50 AM in response to bpali2001
    Level 5 (7,480 points)
    Notebooks
    Jan 31, 2015 9:50 AM in response to bpali2001

    I can't see how an SSD will help if it is unbootable. I think failed PMU resets can cause the firmware to crash preventing any OS loading. If no startup commands are working the Mac is basically bricked. I need to think about the PPC boot process (or you should google for an explanation).

     

    Can you get the boot picker via alt at startup?  I suppose the graphics card could be dead? Have you found any explanation for the LED flash?

    You could find an old Ubuntu PPC live cd & try that too but this seems to be dead before the OS loads.

  • by BDAqua,

    BDAqua BDAqua Jan 31, 2015 11:08 AM in response to bpali2001
    Level 10 (123,496 points)
    Jan 31, 2015 11:08 AM in response to bpali2001

    Still not clear if it's the Mac or the display button flashing...

     

    Can you count the beeps or flashes on the Mac?

     

    1 beep = no RAM installed

    2 beeps = incompatible RAM types

    3 beeps = no good banks

    4 beeps = no good boot images in the boot ROM (and/or bad sys config block)

    5 beeps = processor is not usable

     

    In addition to the beeps, on some computers the power LED will flash a corresponding number of times plus one. The LED will repeat the sequence after approximately a 5-second pause. The tones are only played once.

     

    Note: In this case, a flash is considered to be 1/4 second or 250 ms or greater in length.

     

    http://support.apple.com/kb/HT1547

     

     

    If one of the Apple LCD displays detects an error condition, the power LED will flash in a certain pattern to indicate the issue.

     

    Pattern Meaning

    short, short, short

    The display is detecting wrong video format or an unsupported resolution.

    Verify that your equipment is compatible and restart the computer. If the issue continues, reset the PRAM.

     

    short, long, short

    Make sure you are using the correct power adapter with the display. This alert will only appear on displays built in 2004 or later which require an external power adapter.

     

    short, short, long

    The display is detecting a backlight error. Check your display's power connections and restart the computer. If the problem continues, contact Apple or an Apple Authorized Service Provider.

  • by bpali2001,Solvedanswer

    bpali2001 bpali2001 Feb 1, 2015 3:01 AM in response to BDAqua
    Level 1 (0 points)
    Feb 1, 2015 3:01 AM in response to BDAqua

    i fixed it myself but yeah thank you guys. the thing was that in g5 towers you gotta place the ram in opposite pairs or something like that.

  • by Drew Reece,

    Drew Reece Drew Reece Feb 1, 2015 8:34 AM in response to bpali2001
    Level 5 (7,480 points)
    Notebooks
    Feb 1, 2015 8:34 AM in response to bpali2001

    You have recently changed the RAM modules? It helps to mention stuff like that.

     

    See Apples manuals - they usually have a user replaceable parts section that covers correct RAM install.

    Apple - Support - Manuals