This is a very long story, but after hours of trying to fix and searching forums, I've decided to ask you guys so please try and help 1 year ago I built my own computer, worked fine until about this august, it started to freeze randomly and crash, I figured it was my processor overheating since speedfan showed it running really hot. I cleared out a bunch of dust and decided to buy a new heatsink and PSU fan, and a new case. While I was at it I bought a new video card because mine was outdated. The video card and case arrived, and I began to transplant my mobo to the new case. Everything seemed to be going well, I did lose one insulator washer, so I didn't screw one screw into the motherboard just to be safe. The first power up didn't do anything, but I soon found the problem and fixed it, and it booted up like normal. After about 2-3 minutes of starting vista, while it was searching for a new driver to the new 8600 GTS, the computer shut itself down, after turning the screen white. The only thing left was my mobo led, lit up green. So I turned the PSU off and then back on, and this time the computer froze while it was loading the bios and shut itself off again. I was afraid I might have installed the heatsink on the CPU incorrectly, but I wanted to make sure, and waited for everything to cool down and turned the PSU on once again. This time I made it all the way into vista and turned on speedfan to check the temperatures, it was reading 20 C and 34 C on my two CPU cores (Pentium D 2.8ghz) but my video card was running at 70 C. I thought maybe that was causing the system to shut down (made sense with the screen freezing) and I looked online for answers. I found some sites that told me to download the newest vista driver, and I managed to download and install that driver while the system was still shutting itself off intermittently. After I got the driver installed it seemed to be working normally, it was going for about 25 minutes without shutting off, and many tests were showing everything working correctly. I tried listening to some music but found there was no sound coming out of the speakers (I use my onboard sound)or my headphone jack on my case, so I installed a new driver for the onboard sound. When I restarted my computer, it blue screened loading vista (IRQL_NOT_LESS_THEN_OR_EQUAL error) and then the next time I tried starting my computer, everything spun like normal, all fans worked, HD was spinning, GPU fan was spinning, DVD tray opened and closed, and the MoBo light was green, but nothing showed up on the screen. My motherboard wasn't even going through post anymore. I tried my old video card in both slots, I tried different hard drives, and switching my ram into the other two slots, I cleared my RTC ram cache, and nothing could get the bios to show up on my monitor. I went to sleep after working on it for many hours. This morning the condition hadn't improved, so I removed my battery and then replaced it. The next time I powered on my PSU nothing seemed to work, no fans spin at all, HD doesn't spin when connected. The only thing that has life is my Motherboards green LED. I'm not sure what could have caused all this, but I think it's between the motherboard and PSU. Possibly the CPU. Thanks in advance. Overview - Fans Don't Spin, Only sign of life is green LED on mobo, nothing shows up on screen (no post).