I'm having a problem that started recently. I have the monitor set to turn off after 5 minutes. Everything else stays on, no sleep, etc... If I move the mouse shortly after the screen goes off, it comes back on and is fine. If I leave it for awhile, it takes forever to come back on, and sometimes it doesn't come back on at all and I have to hard reboot. Now, after the hard reboot, the computer turns on but does not boot. It just sits there. I can only get it to boot if I leave it powered off for awhile. This boot problem also happens during regular reboots. In addition, after turning the computer on, it sometimes turns right back off and stays off. What is the problem here? Thanks.