[Call] and [End Call] buttons don't work anymore

[SammiBoi]

My Call and End Call sometimes doesn't work.... with the exception of these 2 buttons, all other buttons on my phone works fine. This is getting more and more annoying as the frequency of these malfunction have been increasing.

I have a feeling there is something wrong with the wire contact because when it malfunction, buttons won't light up (where as when it is working properly pressing the Call/End Call button will make them light up)

Any idea how to fix this?