Thanks for your ideas. Unfortunately i couldn't give more information earlier as i was waiting for a reply from my girlfriends sister.
It took a little while but i have received an e-mail with the make and model.
Make: Cybermaxx MD95218
Model: Ram2010 Notebook Pc
It seems that she was working on the laptop and she just got a black screen and all the lights went out (on the laptop). When i connect it to the mains with the adapter than the only light that flashes at an interval is the light on the adapter. There are no lights at all on the laptop itself even after a 7 or 8 hours of charging the battery. When pressing the on/off button nothing happens.
So BNT, what you have written in your last reply might be the cause. The laptop is 2,5 years old and i would think its out of warrenty. But unfortunately she is not that quick with finding any receipts etc.
Thanks again. CEJM