I built my new system using the following:
Evga 780i motherboard
Intel Core 2 quad 3.00 GHz Processor
4 2 GB Corsair RAM (8 GB total)
Nvidia GTX 285 1GB GPU
Antec 650 Power Supply
Hitachi 500 GB Hard drive
Window 7 64bit OS
My PC stops running and goes to a black screen fairly often. I check the event viewer to see if there is anything to address after every shutdown. Every time the system shuts down there is an event that says some service has entered a stopped state. It is rarely the same service 2 times in a row and is usually 2-4 services back to back. It wills say something like
Event ID: 7036 The Application Experience service entered the stopped state.
This is my second GTX 285 i have had because the first one was faulty. When i had the old GPU i used to get Nvlddmkm.sys BSOD all the time with no fix to be found.
I haven't tested it with a different PSU due to the fact that the system is only a couple of months old. I will try and get my hands on another one to test it though. As far as the temps I run Speedfan and the PSU never gets over 56 degrees and the CPU stays right around 47 degrees.