Your post is in the right area, no worries.
It sounds like a power issue, especially if you've let it sit outside like that!
If the system is heating up and the affected components are expanding, they can expand to the point where the system loses power - not all too uncommon for some types of systems.
If you're positive that the CPU isn't overheating, it could possibly be bad RAM as well - see if you can download Memtest and run it on the system without any failures, if it fails the test, replace the RAM affected. If no RAM sticks are failing, then it's likely power.