Yesterday, after the internet went out for whatever reason, I came back to find my PC off. Naturally, I pressed the power button, and nothing powered on. Problem.

So, I thought it might be the power supply. I don't have considerable experience, but I have a case fan with LEDs. When I just plugged in the PC, and hit the power button, the LED lit up briefly with nothing else. So, I took in the power supply to have it tested, and it turned out that it was live. I took it down to a barebones system, after reinstalling the power supply, and it still did not POST. So, I switched the RAM sticks, trying each of my sticks seperately, and shorted the power switch, without having any result. After this, I reset the CMOS, without having any luck.

Luckily, I had a second motherboard ready. So, I put that one in there, and placed all of the components in. And, as luck may have it, it POSTed. Unfortunately, I was unable to get into Windows because of significant changes to my hardware.

My actual question is relatively simple. Based on what I have done, does it seem as if the first motherboard is the problem?

I am reasonably sure of this, but due to many stores' refund policy, I want to make sure about it, so as not to waste my money on something I don't need.

My barebones system specs are as follows:

PC2700 DDR333Mhz RAM single stick
2.4 GHz Intel Celeron Processor
FSP200-60ATV Power Supply
GA-8S661FXM motherboard

Thanks in advance. This problem bothered me for most of today and yesterday.