Death of laptop?

OK- the laptop finally gave up on us yesterday. The screen just goes black after 5 mins or so. I am taking it to the technical guy and hope I hope I can retrieve it. Does anyone have any ideas why this might be happening? I have not changed any settings/properties. And oh, it is an IBM Thinkpad made in 2000, was refurbished and I started using it last July. Any info, including where else I could take it to in London would be welcome.

Blogging will therefore be on hold for awhile (I think).