Double keypress issues with 15" 2010 MBP and power button not working.

Hi, am having a problem with a 2010 15" MBP. The Power button is not responding unless i pull the battery and run from mains only. Also when it DOES finally boot the i and o keys both press at the same time (writing io io io io io etc, i=io and o=io) as do the k and l keys (klklkl etc, k=kl and l=kl).

I have reset the SMC but the problems still seem to be there.

Short of running an air duster over the keyboard to see if there is crap stuck in there somewhere does anyone have any suggestions? I thought it would be an SMC issue but i have definitely reset this multiple times (clock goes back to Jan) and the problem is still there!

Many thanks

Andy