Why does my playstation freezes during sony loading screen?

It will start up and act like it is loading, but as soon as it goes to the sony logo screen, it freezes. I have taken the top case off and used a can of air in it and wiped the lens off with a soft cloth.It does not seem to be making any strange noises either. It has been packed up for a number of years in a closet, but it was not damp or hot.