Okay, it might sound a bit hard to believe and I don't guarantee that it will always work (depends on how bad your motherboard's conditions are), but here is what worked for me (at least till now). When I plugged in the computer the led on the motherboard would light up, but when I would press the power button, nothing would happen; therefore I tried a little modification to the power supply and it worked till now. If you are interested, please move on to the next step.
Step 1: A trip to your toolbox
So, what you need is basically quite obvious:
1) An old motherboard
2) A (preferably old) power supply
3) The rest of the parts to function with your motherboard
The tools you will need are basically these:
1) Wire cutter
2) (preferably) Soldering iron
4) Insulation tape or shrink tubing.
You might want a screwdriver in case you want to take out your power supply to easily work on it.
Once you have the above materials you can get started.