Flickering Screen (blanks out and comes back)

Question

Hi all,
since a few days I have a rather weird problem with my mini. The mini is connected via DVI to a Samsung SyncMaster 173T and has been so for the last 2.5 years. Everything worked perfect until....
Scrolling to a website the screen suddenly went blank (black) and after a second it came back. This happened randomly and various places, always when scrolling with the third mouse button (mighty mouse bluetooth). I could not really reproduce it until this sunday. Fresh boot of the mini, start iTunes and browse the CoverArt with the third mousebutton. After a while (~20 seconds) the screen blanks and comes back. If I continue scrolling in blanks more often and sometimes I can also see strange lines flickering through the screen before it blanks. This is 100 % reproducable.
So I thought ok, this is probably some graphic card issue. For verification I started Nanosaur (3D-Game), but here no issues. Works just fine.
I then tried to start the Apple Hardware test from the Install CD (took we a while to figure out how to start it....), but this one seems either not to start or not to give a display after the start. So I can't see the results.
Additional info: Not did I move my Mac nor my screen. Everything is in the same place like minimum 1 year!
What can I do to check the root cause ?

Answer 1

You could try booting into Safe mode (hold down the shift key through a restart until you see a message on the screen that the Mac is starting safe) and run like that for a while to see if the problem goes away or not. If it clears up, then that would imply something about the configuration of your main account is causing the problem. If the problem persist under safe mode, then that would point more to a hardware problem, though I have to say those symptoms are very unique and difficult to account for as a hardware failure.
You could also try using a regular USB mouse for a while, though it's hard to see how the BT Mighty Mouse could cause this. Good luck.