Chosen Solution
The computer works greats at startup then after a few minutes, less than 5 min, screen goes blank. Mac doesn’t shuts down, it keeps running because lights are on, can hear hdd or see and access computer on home network but screen doesn’t show anything. It just shuts down. It’s not the monitor because it works/stays on other computer. I also have Windows on bootcamp and there, the monitor stays on all the time so i can’t figure out why under MacOS it doesn’t stay on. Any help? Thank you MacPro : 1.1 (early 2008) OS : Yosemite
it usually means it is set to do that. go to System Preferences > Energy Saver > set your desired values. That should make it work.
