2011 iMac 27" went off with a snap

Discussion in 'Mac Basics and Help' started by 3wood, Jul 22, 2019.

  1. 3wood macrumors member

    3wood

    Joined:
    Jun 13, 2012
    Location:
    Henrico, VA
    #1
    This iMac is my old war horse. Core i7 3.4, 20GB RAM, High Sierra. 500GB Samsung ssd and also has the original 1TB hdd inside. The ssd is adequate for all my needs so the original 1TB hdd is for backup purposes. I also have a CCC clone backup as well as Time Mach backup. I did the install of the ssd myself 2 years ago and all has been excellent with the puter until last night.

    I was reading news on the internet and out of nowhere I heard a pop (or snap), and the screen went black though I could see a bit of light around around the edges telling me that the computer was still running. I couldn't do anything with it so I shut it down and restarted.The restart began as normal showing the status bar letting me know that the SSD was loading. About three quarters of the way across, the status bar stopped and the screen went completely to white.

    I restarted holding down the option key.The icon of the SSD and also the icon of the internal 1 TB drive both showed. I selected the SSD icon and hit return. I got the same situation again where the status bar stopped halfway across and then the screen went to white. If I continued to let the computer run, it went into a loop of the same thing I have described happening over and over again. I shut it down and restarted again holding down the option key. This time when the drive icons came up, I selected the internal 1TB drive one of whose 3 partitions contained a CCC clone of the ssd but the whole process started over again with no improvement.

    Later, I tried connecting an external hdd that had another CCC clone on it and while the icon of the external showed up while holding down option, the same thing happened as happened all the other times before. I have tried starting up in safe mode but nothing I do will allow me to somehow get to disk utility and possibly run first aid. I also tried booting from a High Sierra install flash drive - no luck. The computer doesn't shut down unless I hold the power button down. If I do not shut it down that way.The top of the case feels extremely hot after about 10 minutes.

    Last thing to tell you (and maybe I should have mentioned it first), I had been using a vcr recorder connected to a Vidbox (analog to digital converter) and it was connected to a USB port on the computer. Although I was not converting any vhs tapes to digital at the time the computer made the pop noise, the Vidbox was receiving its power via the USB port. Earlier in the day and also the day before I had done some vhs to digital conversions without any problem.

    So I'd be glad for advice or opinions before I call Apple or otherwise try getting the problem diagnosed.
    Lastly, sorry for the length of this post. Wanted to give you something to go on. I've been using Apple computers since the IIe and luckily I've never had this happen before. Many thanks for your thoughts.

    Reed.
     
  2. vkd macrumors 6502a

    vkd

    Joined:
    Sep 10, 2012
    #2
    Sounds like a capacitor on the video card exploded. Overload or got to hot possibly. It'll still do basic graphics but can't present the full GUI, same thing happened to me on my 2011 iMac. I bought a used identical video card with heat sink assembly on eBay and swapped the old one out.
     
  3. 3wood thread starter macrumors member

    3wood

    Joined:
    Jun 13, 2012
    Location:
    Henrico, VA
    #3
    That makes good sense. About 3 years ago Apple replaced a video card in this same computer for free. The free replacement deal most likely is expired. I'll check if there's any warranty left on the replacement. I looked on ebay. Looks like these go for around $320 new or $230 refurbished if it is the APPLE IMAC 27" A1312 Mid 2011 RADEON HD 6970M 1GB GPU VIDEO CARD. I'll look for a used one. Is what I'm after the one pictured? Thanks for taking the time to answer. Screen Shot 2019-07-22 at 4.50.24 PM.jpg
     
  4. vkd macrumors 6502a

    vkd

    Joined:
    Sep 10, 2012
    #4
    Yes, that's the one, only for me it was a 6770M card as my machine is the lower i5 model. You'll need to read up and watch a video on how to do it, its not so difficult, you just need a cool head and some patience LOL. Oh, a pair of suction cups to take the front glass off are handy, though I believe you can prise it off with your fingernails, or so they say. One of those multi-bit screwdriver sets is good too. I got one with 31 different tool heads in it, it includes all sizes of those six-pointed star drivers that you'll need.

    Hope it works. Good luck!
     
  5. 3wood thread starter macrumors member

    3wood

    Joined:
    Jun 13, 2012
    Location:
    Henrico, VA
    #5
    Yep, I have the tools after installing the ssd 2 years ago so I believe I can do this. Looks like I can get a used card with heat sink for around $170 shipped. If I can get it done and have it back in top condition, I'll consider passing the 2011 on and maybe moving up to a 2014 or so. Would be a gentle but affordable step up. Kinda like the 5K screen and the faster usb ports among other things. Will miss the all in one aspect optical drive though. Well, give to get. Sure appreciate your input.

    Reed.
    Yep, I have the tools after installing the ssd 2 years ago so I believe I can do this. Looks like I can get a used card with heat sink for around $170 shipped. If I can get it done and have it back in top condition, I'll consider passing the 2011 on and maybe moving up to a 2014 or so. Would be a gentle but affordable step up. Kinda like the 5K screen and the faster usb ports among other things. Will miss the all in one aspect optical drive though. Sure appreciate your input.
    Reed.
     
  6. 3wood thread starter macrumors member

    3wood

    Joined:
    Jun 13, 2012
    Location:
    Henrico, VA
    #6
    Howdy all, I'm holding back on using my favorite profanities.
    Started this thread https://forums.macrumors.com/threads/2011-imac-27-went-off-with-a-snap.2190857/
    back on July 23rd. Not sure if I should have continued this there or start a new one. Chose to start this new one.

    My mid 2011 iMac 27 3.4 i7 20GB RAM, 500Gb Samsung SSD + its original 1TB HDD I left in when I put in the SSD. Running High Sierra......anyway I was using it and I heard a little pop. Screen went to black.

    Nothing I tried would revive it. When I would start it up, it seemed to behave perfectly.....normal chime and I could hear the usual sounds from inside but screen stayed black. As a result of my previous thread and the much appreciated help I got there...I bought a used vid card and heat sink. Opened the iMac. Had to remove mother board because vid card/ h sink screws were on the back side of m board (couldn't be on the front of course). I put in the new used board/sink combo, replaced mother board and reconnected all cables, put RAM back in. When I plugged in the 4 cables between mboard and LCD, I ruined the screen display flex cable. New one arrived today from Amazon. I plugged in the LCD and with great anticipation, plugged in the iMac and hit the power button.

    No new results. Puter started right up making all the right sounds but screen is still black. I shined a light on it to see if I could see anything on the desk top - nothing. Plugged in a wired keyboard and hit the Fkey to increase brightness - still nothing.

    At this point, I can't be sure my original vid card/heat sink was bad since trying a new/used one didn't help. I'm confident I did well as to removing the mother board and later replacing it and successfully reattaching all plugs/cables, reinstalling RAM etc. because startup sounds normal. I was extremely carefull to make sure I got the exact replacement parts for this particular machine.

    So that's where I am. Though this iMac has age on it, it's a terrific machine I've always enjoyed and I really want it back in action.

    I'd be greatful for trouble shooting advice or ideas. Maybe it's time to turn it over to a pro or atleast take it somewhere for a diagnosis.

    Thank you,
    Reed. Below - old and new parts and pic of the teardown.

    IMG_7627.jpg
    IMG_7622.jpg
     
  7. Fishrrman macrumors P6

    Fishrrman

    Joined:
    Feb 20, 2009
    #7
    Frankly ....

    I wouldn't spend another cent on it.

    It gave you 8 years of good service. That's not bad.

    Time to start shopping for something new.
     

Share This Page

6 July 22, 2019