Mac Mini 2012 startup jitter after 16GB RAM Upgrade

Discussion in 'Mac mini' started by oneinten, Apr 4, 2013.

  1. oneinten macrumors member

    Joined:
    Mar 16, 2013
    #1
    Hello,

    I just upgraded my Mac mini 2012 to 2x 8GB sticks of Crucial DDR3 1600mhz ram. After the first install the OS booted up into it's normal state, but in doing so I experienced some "jitter' for lack of a better word!

    Once the aple logo has been displayed, my screen flicks to black for a second then my desktop screen appears but the mouse moves "jerky" until a second later then all is well.

    I have run the Mac Hardware test by holding down 'D' during start up.. and all appears fine.

    THe ram is noticed by my machine correctly under "about my mac"

    I don't remember the startup being like this with the original 4GB of ram so I wanted to ask if that's all normal before swapping the ram back out and testing again?

    Thanks!
     
  2. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #2
    It is not normal, replace the new with the old RAM and see, if it continues. A reinstall of the OS is not necessary.

    If the jitter is gone, return the RAM and get new RAM.
     
  3. oneinten thread starter macrumors member

    Joined:
    Mar 16, 2013
    #3
    Thanks, I put the old Ram back in, and the black screen before showing the desktop seems to be consistent with both, so that must be my monitor re-adjusting to the mac's settings or something, I'm using an HDMI connection if that matters?

    The jitter wasn't present with the original 4GB ram, but upon re-testing the 16gb (in there now) it seems to be behaving the same as the original. I've run the diagnostics test again and all seems to be well.

    Are there any apps I could download to test my RAM and double check it's behaving as it should?

    Thanks!
     
  4. justperry macrumors 604

    justperry

    Joined:
    Aug 10, 2007
    Location:
    In the core of a black hole.
    #4
    Reset the SMC and see if it continues:

    Resetting the System Management Controller - Support - Apple

    Also reset PRAM/NVRAM, I can give you a link but this is as easy as holding Command-Option-P-R at the same time, release all keys after a second startup sound.

    Run Apple Hardware Test to see if the RAM is OK, best way is the extended test, will take an hour or several hours dependable on RAM amount.

    Intel-based Macs: Using Apple Hardware Test
     
  5. oneinten thread starter macrumors member

    Joined:
    Mar 16, 2013
    #5
    Thanks! What does resettings the SMC do?

    and also what is the PRAM/NVRAM?
     
  6. justperry macrumors 604

    justperry

    Joined:
    Aug 10, 2007
    Location:
    In the core of a black hole.
    #6
    Read the link which I gave for SMC, for PRAM/NVRAM:

    About NVRAM and PRAM
     
  7. viktormadarasz macrumors member

    Joined:
    Jun 15, 2010
    Location:
    Madrid,Spain
    #7
    Are you sure you got the correct voltage models? 1.35v instead of 1.5v like mosy rams?
     
  8. oneinten, Apr 4, 2013
    Last edited: Apr 4, 2013

    oneinten thread starter macrumors member

    Joined:
    Mar 16, 2013
    #8
    I bought Crucial Ram from eBay, and the packaging specifies "for Mac" so I assume it's the correct voltage. The RAM slots on the mini have 1.5v etched into them but I can't see a voltage rating on either the memory modules or the packaging themselves..

    How can I find this out?
     
  9. justperry macrumors 604

    justperry

    Joined:
    Aug 10, 2007
    Location:
    In the core of a black hole.
    #9
    Did you already finish resetting PRAM/NVRAM/SMC and ran Apple Hardware Test?
     
  10. viktormadarasz macrumors member

    Joined:
    Jun 15, 2010
    Location:
    Madrid,Spain
    #10
    Crucial supposely should say on its website or ask their support by the product number of the ram modules

    I got into mine oWC ram modules I guess they are 1.35v ma mini 2012 certified and 1600mhz ddr3 ( dont caught me on the exac voltage but i can double check at home)

    but te symptoms of yours Ive seen with screen flickering on a macbook pro with incorrect voltage memory ram module a year before

    thats why i asked... i may be wrong

     
  11. oneinten thread starter macrumors member

    Joined:
    Mar 16, 2013
    #11
    Yes that made no change to black flashing up for a moment but I'm not sure this is my monitor as both sets of ram did this, it's familiar to an HDTV auto-recognising a newly powered on DVD player etc.

    The jittery mouse seemed to be a one time thing as well. All tests have come back to suggest the RAM is fine. I looked up the model number and apparently it's capable of running at both 1.35 and 1.5 so it can't be that.

    bit puzzled but it seems the ram is all good!
     
  12. justperry macrumors 604

    justperry

    Joined:
    Aug 10, 2007
    Location:
    In the core of a black hole.
    #12
    OS X has too many bugs I lately guess, yet I do not have the issues you have with yours, mine is a base 2012 with 8GB RAM upgrade, that's all.
     
  13. viktormadarasz macrumors member

    Joined:
    Jun 15, 2010
    Location:
    Madrid,Spain
    #13
    Do you want me to check the voltage on my OWC Ram in my mac mini? just to make sure
     

Share This Page