Here's the sitch: I recently had a 13" Unibody Polycarbonate Macbook taken in to Apple due to having the infamous cracking hinge issue. I just got it back today after they've replaced the top casing, and when I turned it on and opened up Safari, I got some red markings on the screen and the laptop froze. I rebooted and used it for about 5 minutes and it did it again. Here is a photo of the event in action: It wasn't doing this before I took it in for a repair. So here's my question: Can this be caused by a top case replacement? Let me explain though. I know the "common sense" answer might be that "if it wasn't happening before the repair, and now it is, then it is most likely caused by that." But the thing is, in all past experiences that I've ever seen red artifacts appearing like this, it's been in the case of a faulty graphics card. (Although in most cases, didn't cause the laptop to actually freeze, it just caused the display to replace certain solid colors with pure red.) I've never actually taken a top case off and am not positive of all that it consists of. I know that you can remove the bezel housing the LCD cable without taking the mobo out, but to remove the entire top casing / LCD assembly? Can this repair be linked to this issue that I'm having? Apple did a diagnostics check before going under the knife and all components checked out A-OK, so not completely sure as to what might be causing this. It also seems to happen at random, nothing specific reproduces the issue.