Mouse (BUTTONS ONLY) not working Acer Aspire 5742


I took apart my Acer Aspire 5742 because I was sick of it overheating and dying. Followed tutorial and cleaned fan fine. Reassembled and have got everything running 100% fine...

Except the built in mouse keys! The actual mouse itself is working absolutely fine, just the left and right click buttons won't. Have read it's possibly connected to the keyboard? But that seems to be connected and is working fine. Any help? Really don't fancy taking it all apart again, especially as I have no definite idea on where the keys actually connect!

Have also tried looking in 'Mouse' settings on the laptop and keys don't seem to be disabled/switched off or anything!

Thanks in advance!