I have an unusual but annoying problem with my MBP. The problem occurs often when running my laptop with an external monitor connected, and watching YouTube in Chrome. The problem is that the video will (seemingly randomly) freeze, audio will continue playing, and the computer becomes completely unresponsive aside from the mouse still moving. If I then shut the lid of my laptop, eventually the computer will sleep, but the screen remains black (no backlight) when attempting to wake it up again, although you do hear the CPU fan and HDD spin up like normal.

I have located the exact location in the log files that the crash occurs. The relevant portion is here.

I believe that the point at which the crash actually occurred is here:

15/04/2015 10:44:05.000 kernel[0] NVDA(OpenGL): Channel exception! exception type = 0xd = Graphics Engine Error (GR Error 5)
15/04/2015 10:44:05.000 kernel[0] IOVendorGLContext::ReportGPURestart
15/04/2015 10:44:25.000 kernel[0] NVDA(OpenGL): Channel timeout!
15/04/2015 10:44:45.000 kernel[0] NVDA(OpenGL): Channel timeout!

My question is this; is it:

  • A hardware problem (with the graphics card)?
  • A software problem (with the OS)?
  • A software problem (with Chrome)?

Since the crashes are sporadic, this is unfortunately not easy to reproduce at will, although they happen often enough to be a serious problem.

My MBP is a mid-2010 15-inch running OS X 10.10.3. The graphics card is a NVIDIA GeForce GT 330M 256 MB and I'm using Chrome 41.0.2272.118.

Any help or advice on this problem whatsoever would be greatly appreciated.

  • from here it looks like the Google is the problem! To xross check try with another browser.
    – Ruskes
    Apr 15, 2015 at 16:44
  • I have exactly the same problem, but I don't use Chrome. It seems to be caused by the NVIDIA graphics driver. I also have a lot of glitching on the screen when a second monitor (which works fine) is attached and a window is inactive. I haven't tried a full diagnostic on the GPU yet. Do you have any updates?
    – Silke
    May 27, 2015 at 17:22
  • I have the exact same problem. I get a grey screen and then the only option is to reboot. My log also says channel timeout, and I'm also on a MBP mid-2010, but with OSX 10.9.5 currently. Graphics card is NVIDIA GeForce 320M 256 MB, and I'm using Chrome Version 61.0.3163.100 (Official Build) (64-bit). Did you resolve this problem?
    – Magne
    Oct 12, 2017 at 14:18

1 Answer 1


I ran into a similar issue a while back. You will need to diagnose the video card with a diagnostic utility

1) Download, burn, and boot Ultimate Boot CD. There are a number of video utilities you can run that will test out your video card for you. Since you are no longer booting OS X when you boot this CD, you are bypassing any software issues you may be experiencing from Apple and OS X.

There is a USB Flash Boot Drive option instead of a CD (I personally use this).

This will tell you if your video chip is good or bad. If it fails at any point, then it is a safe bet that you have a hardware issue. If everything passes, it's on to step 2.

2) Install a pervious version of OS X; Mavericks or Mountain Lion will do. The best way is to boot from a USB drive (don't overwrite the HDD in your MBP). A small USB drive is fine 10/20 GB is more than enough. This is just to install OS X 10.9.x or 10.8.x so you can do some diagnostics.

Do a Time Machine Backup First! Just in case you accidentally select the internal drive when doing this procedure.

Do a fresh install of ML or Mavericks on the USB HDD. Let it wipe and partition the drive.

3) Boot from the USB HDD (hold down the option key before the boot chime to select boot device). Install Chrome and watch videos as you normally would. If everything works properly, you have narrowed down the problem to Yosemite. Which means you will probably have to wait for a fix from the folks at Apple.

At that point, you have really only two options: downgrade to Mountain Lion or Mavericks or wait for an update to Yosemite.

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