Hey guys, im having problems with my xbox 360, sometime in January it gave up and gave me the rrod, so i tried fixing it which worked for 40 mins then it started freezing and having lines down the screen, so i gave up and got a new one. Now, ive starting playing gta Iv again and because i used my other xbox for modding, i dont want to void the warrenty on my new xbox to install mods, so i tried fixing up the old xbox (the one which died in january)and so far so good, its working again, apart from one thing which is the fan in the back of it has starting messing around, starting off normally then after about 1 min gradually starts speeding up and up and up, which is kind of off putting as it sounds as it is away to blow up, does anyone know why this is happening/ or what i can do to fix it?