11 Replies Latest reply: Aug 29, 2013 10:53 AM by BDAqua
flacens Level 1 Level 1 (0 points)

So a few weeks ago, I tried turning on my mac and the screen stayed black, and the fans just started going crazy. Haven't been able to get it to boot since. The computer will turn on, but within 15 seconds a red LED on the motherboard stays lit and then 30 seconds later the fans go crazy.


I've taken it all apart, cleaned it with an air gun, put it all back together, tried using good ram in different match slots and no luck.


I'm assuming now its the processor. Can anyone tell by these pics if my processor is bad?


It's a dual core, single processor 1.8 ghz G5 btw, and any help is GREATLY appreciated! A dead G5 isnt good when you're a freelance web designer

 

mac1.jpgmac2.jpgmac3.jpgmac4.jpgmac5.jpg

 



Mac Pro, Mac OS X (10.6.8), PowerPC 1.8 GHz Dual-Core
  • 1. Re: Is my processor toast? (pics)
    fordnats Level 1 Level 1 (0 points)

    I know nothing much about G5's, in fact mine is being delivered as we speak, but I had heard that some of the older models suffer needing the thermal paste replaced on the CPU. Hopefully someone with some nouse can confirm or denounce that for you, maybe you've re-done it already? Good luck

  • 2. Re: Is my processor toast? (pics)
    flacens Level 1 Level 1 (0 points)

    Yes i was told i need to do that before putting it back together...but im not sure if that would actually make the comp start working again...

     

    Thanks for the info though!

  • 3. Re: Is my processor toast? (pics)
    Klaus1 Level 8 Level 8 (44,495 points)

    If your CPU looks like cheese on toast (as yours does) then the CPU IS toast!

  • 4. Re: Is my processor toast? (pics)
    flacens Level 1 Level 1 (0 points)

    That's kinda what i figured! But someone pointed out that it just looks that way because of the thermal paste that is on the processor and now dried up

  • 5. Re: Is my processor toast? (pics)
    Klaus1 Level 8 Level 8 (44,495 points)

    Time, I fear, to start sending out invitations for the wake, and use that for a collection for your new iMac!

  • 7. Re: Is my processor toast? (pics)
    Klaus1 Level 8 Level 8 (44,495 points)

    Yep, that might work!

  • 8. Re: Is my processor toast? (pics)
    Swampus Level 2 Level 2 (180 points)

    That's kinda what i figured! But someone pointed out that it just looks that way because of the thermal paste that is on the processor and now dried up

     

    I think you're referring to my comment on the other site.  I probably should have worded it differently:  I think that any CPU pulled today from a previously unmolested G5 (working or not) would look very similar to yours.  Someone else in that thread used the word "normal".  In this case, though, normal is not synonymous with good.  The better compounds of today are only rated for eight years.  The compounds used during the G5 era were not nearly as good as the ones used today.  They probably started breaking down and losing their thermal conductive properties at around the three year mark.  Any G4 or G5 still running with the original compound is running on borrowed time and could greatly benefit from fresh compound.  It's probably the case that many G4 and G5 CPUs have already failed for precisely this reason.  Some will do better than others for longer.  The purpose of the compound is to fill the micro-imperfections where the CPU die meets with the heatsink.  No two will be the same.  Under a microscope, they're each as unique as a snowflake.

     

    The reason I mentioned that it might be worth a shot to apply some fresh thermal compound and put the same CPU back in to test is because reseating the CPU is an actual troubleshooting step for these symptoms (I wasn't suggesting that fresh compound would bring back a dead CPU).  Given that this is a production machine that you're depending on for your living, I get that you need to get it resolved quickly, though.  To that end, I'll give the same advice that I just gave to someone else.  It applies even more here since downtime is money for you.  Keep an eye on your local Craig's List for a working machine like yours that you can use for parts.  In my local market, dual core G5s are listed frequently for $100 to $120.   When it comes to getting a machine up and running quickly, there is no substitute for having known good parts that you can swap in.  It will also likely save you money.  The service manuals from Apple might list a dozen troubleshooting steps for the same set of symptoms.  They usually seem to be listed in order of cost more than likelihood, but if you're on the wrong side of the "buy parts until it works" game, you can end up spending a lot of extra cash that could otherwise be put toward your new computer.  The folks on these forums can be very helpful when it comes to dialing in on the more likely culprits, but no one is 100%.

  • 9. Re: Is my processor toast? (pics)
    flacens Level 1 Level 1 (0 points)

    Thank you!! Very helpful information. I ordered a used processor with the heat sink attached from Ebay for $50. If that doesn't work I'll try getting the logic board. I'll let you all know how it turns out!

  • 10. Re: Is my processor toast? (pics)
    flacens Level 1 Level 1 (0 points)

    So I installed the new processor and heatsink i got from Ebay...and as soon as i powered it on, I heard the startup chime!!!! And sure enough it's been revived!! Works great and it only cost me $50 as opposed to purchasing a new mac (which would've been nice)

     

    Thanks to all you guys for your input and knowledge!

  • 11. Re: Is my processor toast? (pics)
    BDAqua Level 10 Level 10 (116,480 points)

    Great to hear, thanks for the report!