|The screen getting jumbled moments before it shut down suggest something more serious than stuck in power saving mode. More like failed video hardware. The only way to check is to temporary install a video card and see if that works.|
You could try running the Dell diagnostics and see what that comes up with.
Hard drive do not have power buttons or lights unless it is an external hard disk and then it might have an activity light. Computers have buttons and lights and the big thing sat on your desk with all the wires plugged into it is a computer. The hard drive is just one of many components that are inside the computer case.
message edited by StuartS