Hey guys, Thanks in advance for anyone that can lead a helping hand. I have a MacPro1,1 running Lion 1.7.4 with a ATI Radeon X1900 XT. Obsolete right? My problem is every time i use the comp with something that requires more GFX usage the card will crash. Example: youtube video in fullscreen will crash after 10 minutes or so, if i open The Sims 3 the screen will go a yellowish tint and crash before i get past all the loading screens. Im not sure what this problem is but once it crashes i have to keep restarting the machine until it actually registers the card. Most of the time im sitting there 10 to 20 minutes unpluging the dvi cord, switching it and hitting the power button waiting for it to respond. This problem persist since i first bought the machine before lion existed, only it wasn't as bad in the beginning. Before it only happened when i restarted, i wouldn't get any display but a few more restarts and it would work, now the card is actually crashing and it takes forever to get it to work again. Anyway you get an understanding of the torture iv'e been going through, heres things ive tried to solve the issue. Updated to Lion, Undated to the latest drivers, took the card out, cleaned it and today iv'e tryed buying a brand new card. I bought the Geforce GT 640 and it wont acquire the card at all, no display. Im not really sure whats going on at all, to me it sounds like the GFX is dead but i could be wrong. I thought if a gfx was gone you'd never get a display. So if anyone got some sort of advice i'd really appreciate it, i don't care what it is i just need the machine to work again.