Display will often only light up at strange angles - loose contact?
This has been bugging me for some months, but I guess there should be possibilities to deal with this myself.
So my MacBook's display sometimes just becomes dark (as if I had disabled the lighting, only that I haven't) and will only light up again in strange angles, mostly around 20°. Sometimes it will then stay lit up if I move it back into a normal angle again, but often it won't do this at first try and it often takes me 10-15 minutes to get it back in a way I can normally type and see the display at the same time.
I suppose there is some kind of loose contact. As the MacBook is around 2 1/2 years old now and I didn't buy an AppleCare-Plan, letting this fix at an AppleStore won't fall under warranty I guess.
When I googled the problem, I found that it probably is possible to fix this yourself, but I couldn't find any detailed explanations - I also looked here, but could not find them as well (Sorry if there are and I'm just too stupid to find them :( )
Does anybody know this problem and can tell me what to do, i.e. what parts are responsible for lighting up the display and where there possibly will be a loose contact?