acphot

Q: My Power Mac G5 desktop will not boot up, just getting Apple logo

Hi everyone,

 

I can't get my Power Mac G5 desktop to boot up, all I get is the greys screen and Apple logo, but no spinning wheel? The first event was when the computer froze. I did manage to boot up a couple of times initially but the computer froze again as soon as it finished booting up.

 

I have been reading lots on this forum about this sort of problem and I have tried all sorts but just having no luck at all, please can someone help?

 

I was eventually able to get the install disc into the computer and booted up holding down 'option' (Holding down C did not work)

 

When the computer started with the install disc 1 a window openend with:

1. OS X on the hard drive

2. Mac OS X install disc 1

3. Apple Hardware Test

 

If I click on my OS on the hard drive I just get the grey screen and apple logo.

If I click on the Mac OS X install disc 1 the same, I just get the grey screen and apple logo

 

On the Apple Hardware Test there are two options, quick test and extended test. I have done both several times and everything passed! Initially there was a memory failure so I thought 'brilliant' I have found the culprit! I removed the offending ram and retested, both quick and extended, all passed. So thinking that was it all sorted I hit the restart. aargh! Grey screen, apple logo!!!!!!!!!! Oh dear what a pity I screamed, or words that meant that anyway!

 

I have read about getting into 'Disc Utility' or 'First Aid' but I can't find these options anywhere on the install disc and obviously I can't get into the system on the hard drive for the disc utility as it won't boot up.

 

Also I have tried:

1. Changed the pram battery for a new one.

2. Tried to reset the pram on boot up holding down cmd + option +p + r (I got a double chime but nothing else just a black screen)

3. Tried booting holding down shift button (chime and then sounded like it was trying to start, a bit of clicking which is more than before, but then nothing)

4.Tried booting holding cmd + R (chime but then black screen)

5 Tried booting holding down 'C' with install disc in (grey screen + Apple logo but nothing else)

6. Tried booting holding cmd + option + o + f (up comes black screen, in top left corner some computer script . I typed in 'mac-boot' as suggested on a forum and then return, but just back to grey screen and apple logo.

7. Saw something else about pushing pcu reset button inside the computer (did this no change)

 

Now I have run out of options and scratching head? If the hardware test says everything is ok, why can't I get past the grey screen and Apple logo on either the OS system on Hard drive or the install disc?

 

Any help would be real appreciated.

 

Thanks.

Power Mac G5 (Early 2005), Mac OS X (10.5.8)

Posted on Jun 18, 2016 10:40 AM

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Q: My Power Mac G5 desktop will not boot up, just getting Apple logo

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  • by acphot,

    acphot acphot Jun 23, 2016 6:59 AM in response to BDAqua
    Level 1 (6 points)
    Desktops
    Jun 23, 2016 6:59 AM in response to BDAqua

    Hi, still no luck but….

     

    I just did cmd+option+o+f again and it is still showing system time and date as 1/1/1904. I typed in 'mac-boot' again but this time there was a spinning gear and start up clicking sounds as normal and the computer booted up all the way to my sign in screen as normal! However a soon as I put in the password everything froze!

     

    The computer freezing was actually the first symptom I had when I realised that there was a problem. The first time it froze I shut it down and it rebooted as normal but it then immediately froze again. Since then I have never got past the Apple logo either with the system on the hard drive or disc. Until this morning that is when as stated above it booted up as normal but then froze.

     

    I have tried taking out the original drive and putting in a new one and attempted to install a fresh version of 10.5. It didn't want to know and would not even load the install disc. It just will not get past Apple logo? As stated before I have run a hardware test and everything is passing including logic board which I think is the most obvious candidate for the problem??

     

    I just can't understand why the system date setting is showing as 1/1/1904?  Why the two replacement pram batteries and pram reset or even not being able to start completely afresh with new hard drive and install disc is not sorting out the issue? Together with the fact that the Apple Hardware test is showing everything is okay with the Hardware???

     

    I think that I am going a bit mad!!

  • by BDAqua,

    BDAqua BDAqua Jun 23, 2016 7:13 AM in response to acphot
    Level 10 (123,496 points)
    Jun 23, 2016 7:13 AM in response to acphot

    The Date/Time even with a new battery wouldn't be correct until it booted up & you had an Internet connection & had Sys Prefs>Date & Time set to Automatic update from Internet.

     

    So, is what e're seeing maybe if it's really, really cooled off it boots just a bit further?

     

    If so I suspect the Thermal paste has gone bad, 5 years is about it's lifespan, or the LCS problems if Liquid cooled.

  • by acphot,

    acphot acphot Jun 23, 2016 7:42 AM in response to BDAqua
    Level 1 (6 points)
    Desktops
    Jun 23, 2016 7:42 AM in response to BDAqua

    It's an old G5 so presumably it will be thermal paste? 2005 so well over 5 years. I don't think its liquid cooled anyway?

     

    The computer was left alone for a couple of days so maybe it had cooled down enough to boot up further? How does one go about replacing the thermal paste or can this not be done? I have never heard of this, my knowledge of computers is limited please could you explain or point me in the right direction.

     

    Cheers.

  • by BDAqua,

    BDAqua BDAqua Jun 23, 2016 9:31 AM in response to acphot
    Level 10 (123,496 points)
    Jun 23, 2016 9:31 AM in response to acphot

    Well, this is about an LCS model, but the Thermal Paste thing should be about the same...

     

    http://www.xlr8yourmac.com/systems/G5_CoolantLeak_Repair/G5_CoolantLeak_

    Repair_p1.html

  • by TheMacMaster20,

    TheMacMaster20 TheMacMaster20 Jun 26, 2016 9:15 PM in response to acphot
    Level 1 (12 points)
    Jun 26, 2016 9:15 PM in response to acphot

    Tell me if this is too complicated. It is almost certainly an integer underflow caused by the Unix epoch. January 1, 1970 is a special day for computers, but 1/1/1904 does something to your Mac, as well as 1/1/1970. Back in the 70s, when the UNIX system and all its friends were being originally designed, the programmers needed a simple way to represent dates and times, without having to deal with all those awkward human things like days and hours and minutes. They just needed a ticking clock that it was easy to do arithmetic on. And the simplest way to do that is just a number, an integer, representing how many seconds had elapsed since January 1, 1970. And we're still using that. All over the place, in pretty much every computer everywhere. it's generally the best way to store dates and times, because it ignores time zones and irritating human things like that, but all you need to know for this is that midnight at the start of January 1, 1970 the date in question is zero. So what happens if you try? Well, if you set your time and date to 1/1/70 12:00:15 A.M. (or 00000000000000000000000000000000000000000000000000000000000015 in a 64 bit processor's BIOS/CMOS clock) (Ignoring all time zones and DST) will cause a integer overflow. Then It wraps around to 0 (in binary code) (If you had a clock and processor that supports negative numbers it would go negative and counts backwards but that's out of the scope of this post.). Than that goes on and on until, well, you either shut down or, well, forever... So there your problem.

     

    GARRET STAND


    Im the one.Technology repair, bug review, and geek of coding.

    Sign.png

  • by acphot,

    acphot acphot Jun 27, 2016 3:49 AM in response to TheMacMaster20
    Level 1 (6 points)
    Desktops
    Jun 27, 2016 3:49 AM in response to TheMacMaster20

    Many thanks for your reply and input, I do appreciate it. Yes, whilst I am understanding the gist of what you are saying about 1/1/1970, I am not really understanding how I can change the date and time? Or even if it can be changed? I can't boot up the computer to change the date and time? Is it possible to do this when the computer won't get past Apple logo? Or is what you are saying is the computer is lost and nothing can be done to correct it?

     

    Thanks.

  • by acphot,

    acphot acphot Jun 27, 2016 9:37 AM in response to acphot
    Level 1 (6 points)
    Desktops
    Jun 27, 2016 9:37 AM in response to acphot

    Hi,

    Booted with  cmd+option+O+F

     

    Typed in '15 00 12 01 01 1970 set-time' pressed return got ok then typed 'shut-down' then return.

     

    Booted up again cmd+option+O+F system date and time now reads as 9/21/2020 instead of 01/01/1904 oops!

     

    Tried other options such as todays date and time, date the computer was made, with and without internet connection and got all sorts of strange date for the system other than the on that I had input.

     

    Obviously typing it incorrectly or meddling with things I shouldn't be with or both! I got the idea from another post about how to input date and time as:

    'seconds minutes hour day month year set-time' Is this incorrect?

     

    Any ideas? thanks.

  • by acphot,

    acphot acphot Jun 27, 2016 10:33 AM in response to TheMacMaster20
    Level 1 (6 points)
    Desktops
    Jun 27, 2016 10:33 AM in response to TheMacMaster20

    Hi,

     

    I now have the computer set to 1/1/1970

     

    After cmd+option+O+F I typed in 'decimal dev rtc 15 00 12 01 01 1970 set-time' return OK

     

    Tried rebooting but sadly no change still just the Apple logo nothing else.

  • by acphot,

    acphot acphot Jun 28, 2016 12:08 PM in response to acphot
    Level 1 (6 points)
    Desktops
    Jun 28, 2016 12:08 PM in response to acphot

    Just an update really, system time setting is now all correct and set to todays date and time. The pram battery is also checked and working correctly. Sadly this has made no difference, the computer will still not boot up past the Apple Logo?

     

    Not pram battery.

    Not system time.

    Not hard drive.

    Apple Hardware Test states that memory, logic board, video card & hard drive all okay.

    Will not boot up past grey screen Apple logo (no spinning gear/wheel) either from system on hard drive or start up/install disc.

     

    Thermal paste problem has been suggested?

     

    Will now send the computer to service shop to see what they say.

     

    Thanks everyone for your help and advice with this, it is most appreciated. Hopefully I can update a conclusion to this at a later date?

  • by TheMacMaster20,

    TheMacMaster20 TheMacMaster20 Jun 29, 2016 10:40 AM in response to TheMacMaster20
    Level 1 (12 points)
    Jun 29, 2016 10:40 AM in response to TheMacMaster20

    Wrong button!

  • by TheMacMaster20,

    TheMacMaster20 TheMacMaster20 Jun 29, 2016 10:38 AM in response to acphot
    Level 1 (12 points)
    Jun 29, 2016 10:38 AM in response to acphot

    Im saying try to set the date to something before 1970 like the current date.

  • by Shaun Ferguson,

    Shaun Ferguson Shaun Ferguson Jul 7, 2016 12:49 AM in response to acphot
    Level 2 (194 points)
    Old Hardware
    Jul 7, 2016 12:49 AM in response to acphot

    I hope your local shop is better than  mine. Mine refuses to look at a 'vintage' machine. I too triedchanging battery - and it worked. But today kernel panic again and can't get past grey screen.

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