The light sensor or something died this afternoon, it isnt working and the screen is working with max bright,i have to push the button of wake /sleep(the button near the pen and headphone hole) every 10 seconds to wake the bright(when the i dont push the button the keyboard works well,but the screen gets black with max bright and i have to push the button again to see something)

it seems hardware error because before it dies the screen got crazy ilumination,
any ideas? I dont want to push the button every 10sec because i love my n900 i use it well,is my n900 dying?is there somenthing that i can do?
Thanks