Had the computer on, all I had going was iTunes. Went out in the garage for a moment, came back in maybe 2-3 minutes later, computer was off. Didn't remember turning it off, I push the power button to turn it back on, and nothing happens. I look inside the case, and the little LED on the bottom corner is flashing, when it used to just be a constant on. Can't get through to tech support and manual describes no such instance.

I would do a tear down and rebuild to see what the culprit is. Its probably your motherboard. If you are lucky it might be just a power surge or power supply. Unfortunately you have to use the plug and pray method to attempt to fix this. You could try to remove the cmos battery on your motherboard for awhile and plug it back in and see if it boots or not.

Removed battery and let it reset; upon putting it back in and supplying power, problem persists. Did a bench test, (nothing but power supply, motherboard and processor) still blinking. I plan on taking the power supply in tomorrow to a place that can test it to see if it's good or not. Have a feeling it's the motherboard, but power supply is cheaper to replace. I have my fingers crossed...