sansa sandisk m240 not working

i dismantle the player and just clear the dust inside the lenses and mantle it and turn on it but no reponse from the player. So i connect to pc and no response from it. The player doesn’t turn on and also not showing pc. I m using win 7 ultimate sp1. Plz some one help me!.

Model: sansa sandisk m240 1 GB.

Try resetting it.