I cleaned the heatsink, CPU fan, and exhaust fan prior to doing any other work on the system yesterday. after the last crash, I checked the heatsink temp with my finger and it was almost cold. When I pulled the fan and heatsink to clean them, I did NOT put more of that gray goo between the CPU and heatsink prior to putting it all back together, but I was also very careful not to wipe any of it off during cleaning. I was also very careful not to touch any part of the CPU itself, not knowing whether or not oil from my fingers would cause a problem. All fans are working properly as I type this, and the covers are off of the tower. The external hard drive, card reader, and my phone were all connected previously with no problems. Now if I plug any of the three in, it's crash city. I think this thing hates the fact that I tried to be nice and clean it up. Thanks for responding.