Power button not working after thermal paste change

Hi everyone,

After deciding to remove the logic board to change the aging thermal paste on my MacBook, I found that the power button no longer works when I reassembled the computer.

I did some Googling and came to the conclusion that the problem may lie with the keyboard ribbon cable. I'm just not sure whether it is in all the way, or whether the cable is actually broken or not.

I also disconnected the battery connector for about 5 minutes and plugged it back in , and then the computer booted properly with the screen, speakers, MagSafe charging etc all working so I assume it is just this keyboard that is the issue at the moment rather than anything else.

I did notice after struggling to put the cable back in that there were a few small scratches on the cable itself, but it isn't torn or anything.

If anyone has any ideas, that would be really appreciated as I've been trying to get this to work for a few hours now.... :/

https://www.dropbox.com/s/087658mr5yr1hq...

https://www.dropbox.com/s/3p0dhwzkie1h4k...

https://www.dropbox.com/s/5jyuei2lskldqd...