Vertical stripes on screen, can't boot into Mac

Discussion in 'iMac' started by mcrazza, Nov 9, 2016.

  1. mcrazza, Nov 9, 2016
    Last edited: Nov 9, 2016

    mcrazza macrumors member

    mcrazza

    Joined:
    Aug 2, 2008
    Location:
    Hobart, Australia
    #1
    Hi,

    Last night I woke up and logged into my Mac (see signature) after 15 or so minutes sleep and resumed watching a video on YouTube. A split second later the screen froze and tiny faint squares filled dark areas of the screen. The mouse cursor was the only thing I had control of. I turned off the Mac, restarted it and saw this:

    IMG_1051.JPG

    Once the progress bar reaches halfway the stripes disappear however the Apple logo and bar do not return either. This is as far as it goes.

    I tried to boot into the recovery disk but the computer crashes and restarts. Text pops up before the Mac crashes:

    IMG_1050.JPG

    I then inserted a USB install drive of El Capitan in order to access Disk Utility, run First Aid and find out if there is an issue with the SSD. There wasn't. The vertical stripes persisted:

    IMG_1047.JPG

    EDIT: I forgot to add that I tried to boot into my Boot Camp Windows 10 partition, however all I saw was a black screen. No load up. Nothing.

    Next up was Apple Hardware Test on Disk 1 of the 10.5.2 install DVD. No problems were detected on the first short test, however the program stopped eight minutes into the long test. I waited 30 minutes but nothing happened. The stop test button was unresponsive too. The stripes are still there.

    I performed the SMC and PRAM resets, tried to log in but got the same results as before.

    Last step: boot into Safe Mode. It worked but the vertical stripes remains:

    IMG_1048.JPG
    IMG_1049.JPG

    As you can see, the stripes does not show up on white backgrounds and the bright portions of the screen. General performance is slower (more like dropped frames) and internet browsers slowly refresh each time there is movement. Viewing log files in the Console I see the name of the graphics card pop up - ATI Radeon X2000 (FYI it's an ATI Radeon HD 2600 Pro 256MB). Some log files are labelled spin, panic and (vaguely IIRC) hold or wait.

    Basically, I have no idea what's wrong. It's not the SSD. The GPU could be on the way out or the logic board chucked a wobbly. It might be a kernel panic too.

    What are your thoughts and what should be my next course of action? Your help and expertise would be most appreciated.

    Cheers. :)
     
  2. redheeler macrumors 603

    redheeler

    Joined:
    Oct 17, 2014
    #2
    A failing GPU is the cause of your problems most likely. The 2008 24" iMacs are prone to GPU failure, but luckily it can be replaced if you manage to find the special GPU it takes for a decent price.
     
  3. mcrazza thread starter macrumors member

    mcrazza

    Joined:
    Aug 2, 2008
    Location:
    Hobart, Australia
    #3
    Yeah, that's what I thought first. Why or how would a GPU failure affect the boot up process? At this stage I'm in between a kernel panic and failing GPU.
     
  4. kiwipeso1 Suspended

    kiwipeso1

    Joined:
    Sep 17, 2001
    Location:
    Wellington, New Zealand
    #4
    It's possible that it's the video drivers from a previous OS X mucking up on the one you're running.
    Try a clean install of OS X and see if that sorts the problem before you check it into a hardware repair place.
     
  5. mcrazza thread starter macrumors member

    mcrazza

    Joined:
    Aug 2, 2008
    Location:
    Hobart, Australia
    #5
    But how can the video drivers located on the main partition of the boot disk affect the screen on an external bootable drive, or prevent booting into a Windows partition via Boot Camp?

    Anyway, I'm trying your method as we speak. I'll post again in T minus 18 minutes.
     
  6. Zenithal macrumors 68040

    Joined:
    Sep 10, 2009
    #6
    If it doesn't work, it's a hardware issue and you need to take it in for repairs.
     
  7. mcrazza thread starter macrumors member

    mcrazza

    Joined:
    Aug 2, 2008
    Location:
    Hobart, Australia
    #7
    It didn't work. Looks like I'll have to drop it in for repairs. Personally I'd rather do the repair/replacement work myself to save on labour costs (I successfully dismantled/reassembled it two years ago to clean out six years of dust build up). No idea still if it's a kernel panic, a failing logic board or a failing GPU.
     
  8. kiwipeso1 Suspended

    kiwipeso1

    Joined:
    Sep 17, 2001
    Location:
    Wellington, New Zealand
    #8
    It is most likely the GPU.
     
  9. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #9
    As others stated, it does look like a hardware failure
     
  10. mcrazza thread starter macrumors member

    mcrazza

    Joined:
    Aug 2, 2008
    Location:
    Hobart, Australia
    #10
    Looking at replacement GPUs on eBay. None available in my part of the world. At this stage my options are pay a couple hundred and wait two-or-so weeks, or buy a secondhand iMac for a couple hundred bucks extra and wait a few days. I simply don't have the moolah for a brand new iMac.
     
  11. kiwipeso1 Suspended

    kiwipeso1

    Joined:
    Sep 17, 2001
    Location:
    Wellington, New Zealand
    #11
    Seeing as it is almost 9 years old, you would be well advised to buy a recent iMac secondhand and enjoy running the current macOS.
     
  12. mcrazza, Nov 15, 2016
    Last edited: Nov 15, 2016

    mcrazza thread starter macrumors member

    mcrazza

    Joined:
    Aug 2, 2008
    Location:
    Hobart, Australia
    #12
    UPDATE
    Last weekend I contacted an Apple repairman who diagnosed it as a GNU failure.

    Unfortunately I just don't have the spare dollars right now to buy a new iMac or even a secondhand pre-2012 revision iMac. So basically I need to replace the video card and that'll tie me over for sometime into the new year when I can get a new Mac.

    It's been very difficult to find a spare video card for my model available locally online as 99% are from overseas sellers. Time and distance are factors so I've chosen the closest and quickest seller rather than wait a month for a cheaper video card. I just can't find a locally available ATI Radeon HD 2600 Pro, however I did find a local seller who has a repaired, re-balled and tested Nvidia 8800GS complete with heat sink. It's AU$400 incl. postage but a necessary cost. It was in the top-end 24-inch 2008 iMac (mine is the "low-end" 24-inch) and was a BTO option for my model, therefore compatibility won't be an issue. All I have to do is swap out one card and replace it with the other.

    Question: Will it even boot up after installation? Will there be any driver issues or does the OS or firmware take care of it? Do I have to reinstall El Capitan?
     
  13. kiwipeso1 Suspended

    kiwipeso1

    Joined:
    Sep 17, 2001
    Location:
    Wellington, New Zealand
    #13

    You could probably get a decent 2011 iMac for around AU$400. However, if you really want to repair an iMac which is nearly 9 years old and probably won't run for much longer anyway, then go for it.
     
  14. mcrazza thread starter macrumors member

    mcrazza

    Joined:
    Aug 2, 2008
    Location:
    Hobart, Australia
    #14
    Definitely not. Not at 27 inches, not on Gumtree or eBay and then posted to Tasmania (vast majority are "local pick up only"). Believe me, I've been scouring for over a week. For 21.5 inches, maybe. But then there's the problem of postage. Most sellers I communicated with were reluctant even after I offered to cover it.

    Anyway I've made an offer to the video card seller on eBay and I'm awaiting his response.
     
  15. kiwipeso1 Suspended

    kiwipeso1

    Joined:
    Sep 17, 2001
    Location:
    Wellington, New Zealand
    #15
    Isn't there a ferry service that you could use to get to Melbourne ?
    You should be able to pickup from Melbourne a reasonable iMac.
     
  16. BeFreeTech, May 27, 2017
    Last edited: May 28, 2017

    BeFreeTech macrumors newbie

    BeFreeTech

    Joined:
    May 27, 2017
    #16
    Last night I woke up and logged into my Mac (see signature) after 15 or so minutes sleep and resumed watching a video on YouTube. A split second later the screen froze and tiny faint squares filled dark areas of the screen. The mouse cursor was the only thing I had control of. I turned off the Mac, restarted it and saw this:

    View attachment 671258

    Once the progress bar reaches halfway the stripes disappear however the Apple logo and bar do not return either. This is as far as it goes.

    I tried to boot into the recovery disk but the computer crashes and restarts. Text pops up before the Mac crashes:

    View attachment 671259

    I then inserted a USB install drive of El Capitan in order to access Disk Utility, run First Aid and find out if there is an issue with the SSD. There wasn't. The vertical stripes persisted:

    View attachment 671260

    EDIT: I forgot to add that I tried to boot into my Boot Camp Windows 10 partition, however all I saw was a black screen. No load up. Nothing.

    Next up was Apple Hardware Test on Disk 1 of the 10.5.2 install DVD. No problems were detected on the first short test, however the program stopped eight minutes into the long test. I waited 30 minutes but nothing happened. The stop test button was unresponsive too. The stripes are still there.

    I performed the SMC and PRAM resets, tried to log in but got the same results as before.

    Last step: boot into Safe Mode. It worked but the vertical stripes remains:

    View attachment 671264
    View attachment 671263

    As you can see, the stripes does not show up on white backgrounds and the bright portions of the screen. General performance is slower (more like dropped frames) and internet browsers slowly refresh each time there is movement. Viewing log files in the Console I see the name of the graphics card pop up - ATI Radeon X2000 (FYI it's an ATI Radeon HD 2600 Pro 256MB). Some log files are labelled spin, panic and (vaguely IIRC) hold or wait.

    Basically, I have no idea what's wrong. It's not the SSD. The GPU could be on the way out or the logic board chucked a wobbly. It might be a kernel panic too.

    What are your thoughts and what should be my next course of action? Your help and expertise would be most appreciated.

    Cheers. :)[/QUOTE]


    Thanks for taking pictures. I have precisely the same pink bars you have and and the booting problem hanging in the middle of the progress bar with my Mac Mini 2011.

    Interestingly this problem occurred several months ago and corrected itself after leaving it on overnight with the bars on the screen. In the morning the screen was white again and it booted fine and worked for a few months. Then again a few days ago the pink vertical bars appeared again during power up and the progress bar again gets stuck about half way during the boot cycle.
     
  17. nambuccaheadsau macrumors 6502a

    nambuccaheadsau

    Joined:
    Oct 19, 2007
    Location:
    Nambucca Heads Australia
    #17
  18. kiwipeso1 Suspended

    kiwipeso1

    Joined:
    Sep 17, 2001
    Location:
    Wellington, New Zealand
    #18

    Thanks for taking pictures. I have precisely the same pink bars you have and and the booting problem hanging in the middle of the progress bar with my Mac Mini 2011.

    Interestingly this problem occurred several months ago and corrected itself after leaving it on overnight with the bars on the screen. In the morning the screen was white again and it booted fine and worked for a few months. Then again a few days ago the pink vertical bars appeared again during power up and the progress bar again gets stuck about half way during the boot cycle.[/QUOTE]

    If you haven't fixed it with a wipe of the system and clean install, then it is your gpu. As your iMac predates 2011, it is almost certainly time to think about a new iMac or the iMac Pro.
     

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