You know it is a hardware issue... but you don't know what until you begin ruling out possibilities.
Most common is a bad memory module, and second most common is the video graphics card or setup.
Retest memory using one memory module at a time, and all your optical drives, audio, modem, etc. removed. If that doesn't work, retest in <SAFE MODE>.
If you can get any normal screens, go to the Device Manager to take a look at all the devices... any yellow or red flags.
Keep a log of what you are testing... Think about each event. As you know, it is a process of elimination... test, and change. test, and change.
Keep good notes. Remain calm. Think through each step. This is a slow process, and you need fast results, but shortcuts and speedy attempts will not get you up and running... whereas logic and tests will.
Where you gonna get parts in five hours on the Fourth of Julie anyway.
