My Y400 ran into some trouble a while back and still isn't fixed but I won't tell what happened to it here as I will post it on a new thread. Simply put, I had to mod the laptop fan so that it would run at 100% speed no matter what. It made the fan run louder but made my temps considerably lower. This is a post to show you how I did the mod. 1. Open up the bottom cover of your Y400 or Y500 2. Locate the cables for the fan. 3. There should be four cables there. One red, one black, one yellow