Laptop wont turn on - Unknown fitting?

[TDPUK]

I have a acer aspire laptop 6935g, it will not turn on when i press the power button. The charger still work's in it but no lights come on or nothing happens when i press the power button.

I unscrewed the back cover and found this had come out.. what is it

 

[pebbly]

Hi TDPUK, the picture is a little difficult to see , could you please post a better ,clearer one