My R key takes lots of pressure to recognize, what can I do?

[Azureth]

With all my other keys I can lightly press them but for some reason I have to press down the R key quite hard to get it to recognize, any ideas? And no, I didn't spill anything on it.

 

[jnex26]

Probably the contacts are dirty or they are wearing out.

disassmble keyboard and clean the contacts with isopropy if theat does not work replace it.