Horizontal lines and Artifacts in Snow Leopard

[Pasi Koivisto]

The only thing I can think of would be that there are problems either with the graphics card or the drivers for it.

Did you do a clean install or a update? Clean installs, meaning wiping the drive before you install, usually works better but updates works in most cases.

What I would do is

1. Boot from the os install disk you got with your computer while holding down the d key. This will boot up into apple hardware test, run the extended test and see if anything fails. If not..

2. Download the latest combo updater from Apple, 10.6.2, and install
that one over your install. Since it’s a combo install it’ll contain complete files of everything that has been updated which probably includes the graphics drivers.

3. If you have a external drive you could try to install the OS on and try to see if a clean install will help with the issue do that, otherwise doing a clean install on internal disk, after doing a bakup of course, can help. In my opinion the best way is to format the drive.

4. Contact Apple.

My 2-bits.

/Pasi
—
Editor, Colorist.
Mac Pro, 4×3 Ghz, 8 Gb ram, ATI 1900XT, KONA 3, Sony PVM20L4, Tangent Devices Wave.

[Craig Shields]

Thanks for the suggestions. I will give them a try today and post back. I also posted on Apple’s forum with no answers. It blows my mind that no one else has had this problem or are willing to speak up. These are the things you fear when upgrading to a new OS. The sad part is that this is the first time that I have done a clean install. I always thought that it wasn’t worth all the trouble. So on top of this problem I realize that there are some apps that I have to upgrade to use some of my favorite plugs.

[John Davidson]

You did run software update first, right? I seem to recall reading about som e imac display issues in the past, but there were software updates that I think addressed them. If that doesn’t work, make an appt at the Genius bar and hopefully you’ll be able to recreate the issue in front of them.

[Aaron Knight]

I have had this problem as well. I actually had it start with leopard & then continue to get worse on Snow leopard. I have a friend who is a Mac genius and he suggested a few standard things that I should try. he thought it could be bad RAM or a failing hard drive. After booting from an external & still having the same issues, and the RAM I have being brand new, he’s thinking a fan might have stopped running and the graphics chip might have toasted itself. He suggested running a hardware test now (if I can find the disc). We’ll see what happens next.

But you are sadly not alone.

[Jason Higgins]

We had the same problem after an upgrade from Tiger 10.4.11 to Snow Leopard. After days of scouring the net, testing hardware, running AppleJack, resetting PRAM, booting back into Tiger (where the problem does not show up), I finally came across this article concerning the ATI X1900 XT video card.

https://www.xlr8yourmac.com/archives/sep10/092410.html#S27417

Here is the Apple Doc for the recall.

https://support.apple.com/kb/ts3420

Jason Higgins
Editor
Point.360 West