HAD BLACK SCREEN REPLACED INVERTER and MEMORY STICKS AND REPLACED HDD JUST TRYING TO GET A OLD LAPTOP RUNING IT STOPPED WORKING JUST OUT OF THE BLUE CANNOT BOOT INTO RECOVERY DISC JUST SAYS OPERATING SYSTEM not found HAVE IT HOOKED UP TO A external Monitor and can see BIOS BUT nothing seems to happen in BIOS JUST WHANT TO SEE IF I CAN GET THIS THING WORKING BEFORE I GET A NEW SCREEN OR AM I WASTEING MY TIME ANY HELP PLEASE THANKS