"Delete" key stopped working (Dell Inspiron 15R 5520)

Hi All,

I have a pretty frustrating problem here - my "delete" key stopped working at all suddenly on my laptop (Dell Inspiron 15R 5520 - W7 Home Premium SP1)

I have removed the keyboard, put it back in but still nothing. I tried to clean the data cable with which it connects to the board, too, but was no good, either. I thought it'd gone loose or dirty or something...

It's not working either under normal or safe mode.

The funny thing is that all the other keys around function properly, including fn keys, prntscr, insert or home, pg up.

Any idea what could go wrong? 

Thanks in advance,

Richard