1 2 Previous Next 25 Replies Latest reply: Nov 9, 2012 2:29 AM by Robert Albury
Robert Albury Level 1 Level 1 (80 points)

My trusty Powermac G5 which has not given any problems since I bought it in 2004 is now very unhappy.

 

 

It began when wouldn't boot. I took it into an apple service place who immediately announced that it was obsolete and they wouldn't be able to do anything but look at it and run a diagnostic.

 

 

They returned it saying it was a faulty memory module and it now ok which it wasn't.

 

 

I can now get it up and running for about an hour when it makes a rasping noise and freezes.

 

 

Letting it all cool down and moving the memory modules around (I have reduced it down to 2 x I gb modules) and it boots and repeats the cycle - fine for about an hour and then freezes with the rasping type noise.

 

 

The fans are all fine and it doesn't appear overly hot inside.

 

 

Any thoughts?

 

 

Whilst I shall be getting a new apple desktop I very much want to keep the G5 going as it will keep going all sorts of peripherals which I occasionally use.

  • 1. Re: powermac g5 memory problems
    BDAqua Level 10 Level 10 (116,480 points)

    Hi Robert, tough to tell, but my guess at this point is that the thermal paste between CPU(s) & heatsink(s) needs replacing.

  • 2. Re: powermac g5 memory problems
    Robert Albury Level 1 Level 1 (80 points)

    You make it sound bad. Is it repairable? Can I buy some paste and squeeze it in? or should I just go out and buy a second hand replacement. There seem to be quite a few around where I live for sale.

  • 3. Re: powermac g5 memory problems
    BDAqua Level 10 Level 10 (116,480 points)

    It requires diassembly.

     

    Replacements are cheap, but of course the thermal paste may need replacing also, since it only lasts about 4-5 years normally.

  • 4. Re: powermac g5 memory problems
    Robert Albury Level 1 Level 1 (80 points)

    Thanks - I guess that's it then. Shame 'cause althoiugh weighing a ton it was a nice machine.

  • 5. Re: powermac g5 memory problems
    BDAqua Level 10 Level 10 (116,480 points)

    Yeah, it's a shame really.

  • 6. Re: powermac g5 memory problems
    Jacumba Level 4 Level 4 (2,325 points)

    Let me give you something to try. The thermal paste has nothing to do with it. Remove the ram from the computer and start the computer up, with no ram in it, and turn it off, you'll probably have to force quit it. Then insert one ram stick in and do a full start up, and turn off. This time you won't have to force quit. Repeat this till you have all the ram sticks back in place. Ram gets corrupted, I've done this on many computers and got them going. It's worth a try. I've seen ram go bad but seldom, usually it's the slot on the motherboard that it fits in, that stops recognizing it.

     

    The symtoms your mentioning though, sounds like a hard drive going bad. When they start to go the computer starts acting erradically and yes freeze up. And it gets that raspy sound. So if you have a spare hard drive and the original OS you could try swapping out a hard drive, if you don't want to give up on this computer that you seem to really like.

  • 7. Re: powermac g5 memory problems
    Robert Albury Level 1 Level 1 (80 points)

    Hi Jacumba,

     

     

    I haven't been able to pursue this for the last few weeks.

     

    Thanks for your suggestions which I am now trying out, although I don't fully understand the logic of some of them.

     

    The reason memory was thought to be a problem int he first place was that the front led was flashing three time - suggesting a memory fault.

     

    The G5 doesn't start up with zero memory.

    Placing the old memory in after re-powering resulted in the first modules not doing anything - the second set I placed in (original pair 256MB) enabled it to startup but not to do anything (I assume not enough memory).

     

    I have followed this with the original pair 256MB plus the pair which wouldn't let it start up just before (pair IGB). It booted and works.

     

    I have done a SMART check on the hard disk which reveals nothing.

     

    I am just leaving it running to see what happens.

     

    Whilst it could well be the hard disk playing up when it went down before the led on the front would always do the three lights flashing and before when I swapped the memory modules around it would work but then freeze.

     

    Anyway all suggestions will be followed as I would like to keep it running if only to maintain OS 10.4 to be able to access a few OS9 programmes and to be able to use the dial up modem.

  • 8. Re: powermac g5 memory problems
    japamac Level 7 Level 7 (24,390 points)

    The three flashes of the power LED in a G5 indicate a RAM fault, specifically "No RAM banks passed memory testing" . Although total failure of all RAM at once is likely uncommon, RAM should be tested with Memtest X or Rember to confirm the condition of the RAM. Testing with Memtest X in Single User mode is the surest way to obtain a definitive test result, especially when RAM faults are intermittent.

     

    RAM utilities other than the two mentioned are generally inferior and can only be trusted if fault is found. Most other test utilities are "all or nothing" and rarely find the intermittent faults which are more common than complete failure.

     

    In machines where the RAM tests good, it is a fairly common condition in G5's to have solder connections failing at the memory controller and/or the RAM slots. These failures often cause the three flash report at failure of POST.

    These machines (those with degrading solder) have limited life left, as is, and will require replacement of logic board or reflow of solder connections for prolonged, continued use.

     

    One additional issue that RAM faults can cause is data corruption. Data corruption can cause a myriad of issues and the use of Disk Utility or Disk Warrior is required to repair the data corruption before system failure occurs.

    Boot to the OS X install disc, select the language to be used, then, in the next window, from the menu bar in Utilities, select Disk Utility. Choose your system drive and run the "Repair Disk" command.

     

    If errors are found and corrected, run the Repair Disk command again.

    After the repair attempts are completed, restart normally.

     

    DO test the RAM.......

  • 9. Re: powermac g5 memory problems
    Jacumba Level 4 Level 4 (2,325 points)

    When you pull the ram out you add "one stick" back at a time and do restarts. Reading your post seems to indicate you were adding them back in pairs. It's important that you add them back one at at time.

    This may not resolve your problem but it has on alot of computers I've worked on.So it's worth the try.

  • 10. Re: powermac g5 memory problems
    Robert Albury Level 1 Level 1 (80 points)

    Thanks again Jacumba.

     

    The latest - the G% ran happily until lunchtime (2.5 hours) and then I put it to sleep. It did not recover.

     

    Again after unplugginh the memory and repluggi it reserected.

     

    I have just run memtest and it looks bad but I cannot interpret the results.

     

    Any further suggestions gratefully received.

     

    regards,

     

    Robert

     

    Mac OS X 10.4.11 (8S165) running in multiuser mode

    Memory Page Size: 4096

    System has 2 PPC processors(s) with Altivec

    Requested memory: 1386MB (1453981696 bytes)

    Available memory: 1386MB (1453981696 bytes)

    Allocated memory: 1386MB (1453981696 bytes) at local address 0x0000000004008000

    Attempting memory lock... locked successfully

    Partitioning memory into 2 comparison buffers...

    Buffer A: 693MB (726990848 bytes) starts at local address 0x0000000004008000

    Buffer B: 693MB (726990848 bytes) starts at local address 0x000000002f558000

    Running 1 test sequence... (CTRL-C to quit)

    Test sequence 1 of 1:

    Running tests on full 1386MB region...

      Stuck Address : testing  1 of 16

    FAILURE! Data mismatch at local address 0x0000000044b8e718

    Actual Data: 0xffffffffba4718e7

      Linear PRN          : testing  3 of 16

    FAILURE! Data mismatch at local address 0x0000000044b8e718

    Expected Data: 0xa268527acb33ab7a, Actual Data: 0xa268527aca33ab7a

    Running comparison tests using 693MB buffers...

      Random Value :   

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0xfffb463e7f757330, BUFB Data: 0xfffb463e7e757330

      Compare XOR         : ok

      Compare SUB         : ok

      Compare MUL         :   

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0xe08ca21a936a86e3, BUFB Data: 0xe08ca21a926a86e3

      Compare DIV         : ok

      Compare OR          :   

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0x1f7fa012a3ffdf8d, BUFB Data: 0x1f7fa012a2ffdf8d

      Compare AND         :   

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0x1f37a01023e91e00, BUFB Data: 0x1f37a01022e91e00

      Sequential Increment:   

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0xf62ed6c0dd270578, BUFB Data: 0xf62ed6c0dc270578

      Solid Bits          : testing  2 of 64

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0xffffffffffffffff, BUFB Data: 0xfffffffffeffffff

      Block Sequential    : testing   2 of 256

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0x0101010101010101, BUFB Data: 0x0101010100010101

    Checkerboard        : testing  2 of 64

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0x5555555555555555, BUFB Data: 0x5555555554555555

      Bit Spread          : testing   1 of 128

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0xfffffffffffffffa, BUFB Data: 0xfffffffffefffffa

      Bit Flip : testing   2 of 512

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0xfffffffffffffffe, BUFB Data: 0xfffffffffefffffe

      Walking Ones : testing   1 of 128

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0xfffffffffffffffe, BUFB Data: 0xfffffffffefffffe

      Walking Zeroes      : testing  25 of 128

    FAILURE! Data mismatch at local BUFA address 0x000000001963e718, BUFB address 0x0000000044b8e718

    BUFA Data: 0x0000000001000000, BUFB Data: 0x0000000000000000

    *** Address Test Failed ***  One or more DIMM address lines are non-functional.

    Execution time: 146 seconds.

  • 11. Re: powermac g5 memory problems
    japamac Level 7 Level 7 (24,390 points)

    Buy a new pair of DIMMs. RAM must be installed in pairs in the G5, as the machines controller is dual channel and balanced RAM is required.

    Power Mac G5: Memory Specifications and Requirements

     

    http://eshop.macsales.com/shop/memory/PowerMac-G5-Memory

  • 12. Re: powermac g5 memory problems
    japamac Level 7 Level 7 (24,390 points)

    It's important that you add them back one at at time.

    That doesn't work with the G5 dual channel controller.

    RAM must be installed in size matched pairs.

  • 13. Re: powermac g5 memory problems
    Jacumba Level 4 Level 4 (2,325 points)

    Don't tell me it don't I just worked with a Mac ram 2 weeks ago.The ram may have to be installed in size and matched pairs for a computer. But I'm referring to a repair of corrupted ram, you add them back one stick at a time.

    So don't post to me unless you know what your talking about. Just because you read something somewhere doesn't mean it's 100 percent accurate.I have a Mac that doesn't suppose to take a hard drive over 50 GB, well I put a 80 GB in and it worked.

  • 14. Re: powermac g5 memory problems
    Robert Albury Level 1 Level 1 (80 points)

    I do not think that it is the memory modules which are faulty.

     

    After I got the G5 To start again I began to load the memory and tested them with Memtest X.

     

    The first two pairs passed without fault but after I put the G5 to sleep it would not wake up and then when rebooting I get the 3-flashing LED.

     

    The memories that passed all have been considered to be faulty before as they have been in the machine when it has failed.

     

    (I also doubt the suggestion that it is the thermal paste as when it has been working I have been monitoring the CPU temp which seems to be perfectly within its normal range.)

     

    The symptoms are still the same - the machine will not boot - 3-falshing LED. Remove the memory and replug it and the machine boots and then later  either will later not wake from sleep or will freeze after a couple of hours. Whilst it is on it appears to work perfectly well with progs like Indesign and Photoshop.

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