so i just got my dads old laptop and it was working fine but it didn't have a sound card or video card and it was kinda slow so i took off a few back panels were i saw the hard drive, ram, and the wireless card which is what i wanted to upgrade. so i took them out and looked ate them and then put them back in but since then the laptop wont boot anything when you turn it on there's power but the screen will stay black even when i hook the laptop to an External monitor nothing shows at all.