Weird Happenings

[imported_Rad]

So, my friend has a spare 512 stick of HyperX so we install it and give my system a go... Well, my HD dies on us... which was kinda random... it just stopped spining... but i had problems with it before so im going to RMA it... Now luckily i have 2 HD's in my comp, and the one that works has my windows on it... anyways, now i have a problem with black screening while idle... my computer stays on and fans etc work, but the screen is black... but this only happens when my computer remains idle for a few minutes... any ideas? I mean, i think its obvious that my memory may be messing stuff up, but its weird that its only while idle...