Horizontal glitches only on start up

Discussion in 'MacBook Pro' started by stooie3000, Oct 15, 2014.

  1. stooie3000 macrumors newbie

    Feb 24, 2014
    Hi everyone,

    I hope somebody might be able to help me with a problem I'm having with a late 2013 13" Macbook Pro. I'm afraid the story isn't short, so apologies in advance.

    I bought a 2013 13" Macbook Pro refurb from Apple in August. On the first day I started getting these weird horizontal lines during the transition from the Apple logo to the desktop, so I booked it in for Genius Bar appointment. The guy I dealt with was very helpful and said it was either an OS install problem or a GPU problem and suggested I return it for a replacement. I did so, and received my replacement that week.

    A day after receiving the replacement, it started doing the same thing (on the first reboot - I set it up fresh so didn't restore from backup or anything). I would have thought the likelihood of getting two machines with a hardware issue is fairly slim. Taking the Apple genius at his word, I downloaded a fresh install of Mavericks using internet recovery, and wiped the hard drive with Disk Utility to do a clean install. After all that, it was still doing it.

    The problem is intermittent, and only seems to happen on boot up. Once the machine is up and running, it seems to be ok. I tried SMC and PRAM resets and funnily enough, a PRAM reset will always reproduce it.

    SO, I took the second machine in to the Genius Bar, and dealt with someone rather less helpful. First he blamed me for running 'Third Party Software' - MS Office and BetterTouchTool were the only things I had installed and I've never had problems with either of them on any of my other machines. Also, it was doing it after a clean install of Mavericks, so I don't believe this is the issue. Then he said that it's normal sometimes as the 'graphics driver is loading', but I've never had this on any of my other macs and I've never come across it online. They did a hardware diagnostic which came back clear. Eventually they took it in and installed a 'Known Working System' i.e. did a clean install of Mavericks with their own system image. This seemed to do the trick as it wouldn't do it even with a PRAM reset.

    Four weeks down the line my macbook has, unfortunately, started doing it again. I've even tried installing the public beta of Yosemite and it does it on that too. Has anyone come across anything like this before, or able to shed any light on what the issue might be? Is it possible that Apple's Hardware Test might not pick up a GPU issue? If it is a software issue, why does it persist after clean installs of Mavericks (and Yosemite public beta)?

    Apologies again for the huge thread! I've attached a picture of what it looks like. Sometimes it has the horizontal grey lines and the bottom quarter of the screen is a garbled white.

    Thanks in advance,


    Attached Files:

  2. nudoru macrumors regular

    Feb 27, 2012
    Completely random suggestion, but maybe it's your power? Does it do it on battery or plugged into different outlets?
  3. stooie3000 thread starter macrumors newbie

    Feb 24, 2014
    Hi, thanks for the quick response. It does it regardless of whether it's running on battery or plugged in to the wall. I have two genuine Apple chargers which I've used at various locations and it will glitch regardless... Thanks for the suggestion tho!

    Kind regards,

  4. Gav Mack macrumors 68020

    Gav Mack

    Jun 15, 2008
    Sagittarius A*
    I would hazard a guess that's gpu related from a cold boot - which post pram reset is also a cold boot - I've seen similar patterns with older macs but normally they are coloured and not grey though.

    Solder issues with a defective ball can come and go after movement and the hardware tests Apple do are always inadequate. If you still have warranty I would give your GPU a nice stress test with furmark which taxes and cooks your GPU far more than the AHT ever does.
  5. oplix Suspended


    Jun 29, 2008
    New York, NY
    This could be a sign of a hardware defect in the graphic core or memory. Also if I ever heard an employee at an Apple store blame me for running third party software, his manager would not be happy.

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