Wdect 2315+1

Check if the screw of the phone is not too tight, because the button might press by itself if it is too tight.

If the problem is not solved,what I do in a situation like this is to loose the phone and use cotton wool or soft brush to clean it with a little mentholated spirit, leave it in the sun to dry, after drying, allow it to cool a bit and couple it back.

You should not clean the screen with spirit, you should clean only the board and the keypad also. Just a little spirit and don't let it be too much. You can dry in any other heat apart from sun and don't allow it over heat.

I wish you the best.