Okay, you’ve checked the simple stuff and now you know for sure something is "bad broke". Here's what to do to next. There are two ways of diagnosing computer problems:
METHOD #1 - TROUBLESHOOTING TO THE "BAREBONES"
This method, while not the quickest way to identify defective hardware parts is the most basic and the most foolproof.
A "Barebones" is a computer that has been stripped down to the minimum items needed to boot up (power supply unit, memory, video card and motherboard + CPU). No, you really don't need the metal/plastic computer case. I have run a barebones computer setup sitting on a cardboard box!
METHOD #2 - TROUBLESHOOTING WITH FLOWCHARTS
With this method, you can just follow the diagrams and let them lead you to the correct answer. This method is very quick, very straightforward and requires the least amount of time messing around in the computer case.
It also one of the only ways a home computer user can analyze a defective laptop! Flowcharts can also be used determine software problems as well.