11 Replies Latest reply: Jan 31, 2012 10:44 PM by BDAqua
andrewlatona Level 1 (0 points)

So for a while I've been experiencing graphics problems so I ordered a new graphics card off eBay and some more RAM - can't hurt, right?


Finally today it arrived, so I picked it up, watched YouTube videos on how to properly remove and install new graphics card and RAM, then proceeded to begin.


I did everything and with ease.  I even reset the PMU after installing the two new 1-gig DIMMs ( now making my computer have 6.5 gigs) and waited a couple minutes.


Upon plugging in the power cord, the tower begin to click non-stop.  The machine does not turn on.  I removed what I installed and reinstalled it, reset the PMU for the 2nd time, and even took out the battery and hooked it up to a multi-metre to make sure it still has the right voltage... all to no avail.


I have no idea what is happening and I'm beginning to lose all faith in technology altogether.


Can someone please, for sanity's sake, help me??



~ A

PowerMac, Mac OS X (10.5.8), PowerMac G5 Dual 2Ghz
  • wayne146 Level 1 (60 points)

    First I am NO expert, actually an idiot. but from what I've read monitoring the Power Mac discussions, it sounds like your looking at a mis-matched ram problem to start with, there will be more proffessional help coming soon, But G5's need matched pairs installed in proper order, as I recall you have 8 slots, starting from the center going out, the 2 center slots are, 1 & 1, yes, the same # for both, then the next 2 on the outside are 2 & 2, the next outward are 3 & 3, then 4 & 4.   So it looks like this; 4, 3, 2, 1, 1, 2, 3, 4.


    Pull them, match them, and reinstall in proper order, may cure all problems ???


    I don't know ( again just bad recall, I don't have a G5 ) but 6.5 gigs of ram sounds odd to me.


    BDAqua will be around shortly to give expert advise.

  • BDAqua Level 10 (121,670 points)

    I think Wayne may very well have you covered with the RAM needing to be opposing pairs. Is it Mac Compatible RAM?


    Can you count the beeps or flashes?


    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.



  • old comm guy Level 4 (2,240 points)

    A question and a comment here on your problem.  The question is what is the nature of the clicking?  That is to say what frequency of clicking are we talking about...once per second, faster, slower, is it rhythmic?


    There are several relays in the G5 power supplies.  One should click once when mains power is applied to the unit.  This is accompanied by the appearance of a +5 volt standby voltage on pin 1 of connector P1.  That's probably the relay you are hearing when you connect power to the machine.  An overload or shorting condition may be detected which could cause the cycling on and off, though I am not entirely sure.  The G5 power supplies have a number of quick-acting protective circuits, though in my experience this occurs while the machine is in the actual boot or wake process.


    With respect to measuring the battery, the "official" method of measuring the battery voltage is to measuer it in the holder with mains voltage removed from the machine, anything below 3.3 volts indicates the battery should be replaced.


    As a first experiment, disconnect all peripherals and remove the new video card, then see what happens when you plug in the machine.  We can go from there.

  • Texas Mac Man Level 8 (46,560 points)

    Does the clicking occur when you just plug in the G5's power cord, or does it occur when you attempt a startup?


     Cheers, Tom

  • andrewlatona Level 1 (0 points)



    You're right about the RAM configuration but I don't believe my problem stems from misseated DIMMs.

  • andrewlatona Level 1 (0 points)

    Yes, the RAM I installed is the correct type and is seated in the correct configurations.


    I think I may not have made myself clear:  I am encountering actual clicks rather than beeps.  I have heard an example of those beeps you mentioned with my old G4.


    When I installed the hardware, as we're taught, I did so with the machine unplugged from the wall.  The clicking occurs once you replug the G5 into the wall outlet.  The clicking comes in very quick spurts of two, in perfect intervals every 2 seconds.


    After writing my initial post here, I thought I should try replacing the new graphics card I got today with the original one.  I did so and once I reassemble the machine and plug it back in the repeat clicks stop;  I only experience the normal double clicking sound from when alternating current is reintroduced into the machine.


    This leads me to ask for further assistance:


    Let me describe the issue which lead me to order a new graphics card (and additional RAM) to begin with.


    I bought this G5 PMac used and it never gave me issues in the beginning of me owning it.  However, I quickly began experiencing display issues.  Specifically, from time to time, when I boot the machine the displays wouldn't kick in.  I knew (and continue to believe) that the machine itself functions normally (this theory is based on the fact that you can hear the audio fine:  Skype launching - the issue is simply that you can't see anything).  I though this issue centred around the fact that I was using two old CRT monitors so I bit the bullet and bought sleak new flat screens... to no avail. 


    After months of deliberation and frustration, I've been lead to this point:  a new graphics card (which apparently doesn't work), and a persisting graphics output problem.  (Note:  this is my diagnosis - I haven't asked a professional to physically look at the machine).  I'm assuming I installed those two new 1gig DIMMs properly because upon reinstalling my original graphics card again, the machine seems to boot fine, yet I'm still encountering zero display.


    I should note that from time to time I'm able to "trick" the computer into catching my displays.  I do this by booting the machine without the monitors attached, and while it begins to boot plug the displays in.  This method has a success rate of 30%, and I'm currently sitting within the other 70% without any display and am unable to check "About This Mac" to see if my new RAM install took or not.


    Any help is so appreciated.


    Sorry for the novella,



  • wayne146 Level 1 (60 points)



    Novella's are ok, they often disclose the real problem in the story line.


    I was thinking you might have had miss-matched dimms as pairing goes, preventing start up, and only possibly the clicking might be related.


    In reading your story, I see you don't mention the make, model or other fine details of which Graphics  card you bought, and since you know it's related to not booting and the clicking, one must assume the card is bad, or not for a Mac.


    Posting which card you bought is now essential to fixing your G5, with the source and other details.


    "Japamac" is the resident expert on graphics cards, he should be along as the time line gets to side of the globe.


    You might want to repost this with the words "video card" or "graphics card" in the title line, to grab his attention.


    He has a website with video cards listed, starting with low end at top, and best performers at the bottom.

    Check it out, tons of knowledge, and great photo's for all to see.





  • BDAqua Level 10 (121,670 points)

    Great additional info from both you & Wayne, thanks!


    Does it boot into any of these modes? & display?


    Holding Option/alt key at bootup.


    Holding SHIFT key at bootup.


    Target mode...




    Does it boot to Single User Mode, CMD+s keys at bootup, if so try...


    /sbin/fsck -fy


    Repeat until it shows no errors fixed.


    (Space between fsck AND -fy important).


    Resolve startup issues and perform disk maintenance with Disk Utility and fsck...




    We might get clues with verbose mode...




    Does it boot into Open Firmware (mode)  with CMD+Option+o+f ?




    reset-nvram (press Enter)

    set-defaults (press Enter)

    reset-all (press Enter)


    Have you done a PRAM reset, CMD+Option+p+r...




    How to reset the SMU/PMU on a Power Mac G5 (Late 2004) or Power Mac G5 (Late 2005) ...




    Earlier G3, G4, G5 models...




    Might be time to replace the PRAM Battery, 4 years is close to their lifespan, far less if ever without AC power, & can cause strange startup problems...


    See which one your G5 has...





  • Ramón G Castañeda Level 4 (1,460 points)

    What Wayne says.


    To expand just a bit, if the seller did not explicitly specify the card as being for the Mac, then it is not a Mac card, meaning it was not designed or made for a Mac nor has it been flashed (hacked) to work on a Mac.


    Often, PC cards that are flashed to work on a Mac need to have some of their pins electrically isolated by taping them.  If the tape falls off or is otherwise not present on an otherwise-flashed-for-Mac card, the card will fail on a Mac, very often producing the clicks you describe


    I had a mutant, flashed card lose the virtually invisible tape and my old G4  instantly made the clicking sounds and was completely disabled.


    I'm currently happily running mutant, flashed cards in my G5 Quad and my DB DP MDD G4.  Nothing wrong with that. 

  • old comm guy Level 4 (2,240 points)

    OK, I am convinced that the new video card has problems, as it appears the power supply is starting its standby voltage, detecting something bad on some supply rail and kicking the standby voltage back off, then trying again in two seconds,  I can't think of a scenario where bad RAM would cause that to happen, even RAM that is not correctly located in the DIMM sockets, as you would normally get the flashing LED activity in that case.


    Now, that being said, one thing that can be problematic in G5 power supplies is dust-bunny buildup.  As I found almost two years ago, an amazing amount of junk can build up in the power supply due to its location at the bottom of the machines and the fans pulling cooling air in from front to back.  The best solution is to remove the power supply unit and blow the dust out with clean dry air.  Canned air will work, but it might be advisible to remove the cover for complete cleansing.  For some pictures, see the link in this discussion:




    Too much crud will affect the operation of the supply and trip protective circuits unnecessarily.


    And needless to say, any blowing out of dust should be done outside!

  • BDAqua Level 10 (121,670 points)

    Great old post, thanks OCG!