I am currently having a bizarre batch of problems relating to my iMac's display. I have a white 2.16ghz Intel Core 2 Duo iMac with 3 GB of ram. I have made 2 hardware modifications: 1 500GB hard drive self-installed (to replace the stock 250GB HD) and the installation of 1x2GB & 1x1GB 667mhz DDR2 memory. I installed a trial of Adobe Photoshop CS4 a couple of weeks ago. The problems began after that with the system's display completely locking up (though the machine was still operating i.e. the volume function on the keyboard still worked). I figured it had to do with Photoshop's new usage of the graphics card, so I disabled that to see if it would help, it did not. Other symptoms: Random lines (like TV scan lines) across the screen in specific applications in no particular order that sometimes disappear on their own or after the app has been closed and restarted (as seen here: ) Random splashes of magenta and yellow coloring over certain graphical elements that disappear just as randomly as they appeared (either by a click of the mouse or typing on the keyboard) Random manipulation of textual information on the display Progress bar for copying, etc. actions displayed off-center Complete screen blackout that requires machine restart to function again Mouse freezing that requires unplugging and plugging in again for mouse to return to normal operation All of these problems began after the installation of CS4 and were not present before. I have removed CS4 and the problems still occur randomly, although things seem to be getting worse. I've checked the Console for any sign of problems but the logs have not produced anything worthwhile, which makes me believe this is a hardware problem. I purchased the system in November of 2006 from my university's campus store and as they have their own repair center did not purchase Apple Care and also assume my warranty is expired. As I am an alumnus of that university and not currently attending I no longer have access to the campus store/repair center. So, that said, what are my options given this information? Obviously there is some sort of problem with the graphics card, is this something that can be replaced or does it require a full logic board replacement? Can this be taken into an Apple store for repair, even though I've taken the machine apart to install a new hard drive? Thanks for your advice in advance!