Toshiba satellite a505-s6960

Hello,
I have been having problems with my laptop for a while now. I hadn't used it in a while, because theI battery wasfull bad, but I got athe new batterythings and tried to start it up the otherday. Everything seemed to work fine, except then Windows wouldn't open. The logo would come up, but just as the login screen should have been appearing, the screen would go black and the green power saver light would come on. To make a long story short, I opened up my computer and disconnected the CMOS battery. I heard that it might be fine without one. Now my computer powers on, but the screen doesn't kick on at all. And the hard drive doesn't seem to be working on anything. Is this happening because I removed the CMOS battery, or did I mess something up when I opened up my computer? I disconnected and reconnected several cables in the process. What could be the cause???