Volume Button

I wasn't sure where to put this but I hope this is the right place.

The problem is on my Dell Latitude D810 I have buttons above the laptop's keyboard that can lower or raise the volume and mute it right next to the power button. At first these worked but now only the lower volume button works and the raise volume button only works if I press it several times (then it goes up one notch). Is there something I can do to fix that? I don't know what could have caused it.

 

since you said it works but after pressing it several times so it could be that the button is messed or not working proper that the button is not in tact in its place. the other reason could be it that the button is set that it raises the volume little after pressing several times which could be checked from the dell's easy access functions which should either be located on the right side of the taskbar or in the control panel.