NES Troubleshoot Help

So last night I tried firing up my NES after about a year. all I was getting was a flashing grey screen and blinking light on the system. I read a bit online and the suggestion seemed to be to take out the 72 pin connector, boil it, and clean it with some rubbing alcohol.

I did that this afternoon.

Now I'm getting a flashing title screen for every game I try. I guess that's a step in the right direction, but I don't know what to try from here.

EDIT: About 90% of my games started working today without doing anything else so it all seems good. With only a small percentage not working I have to assume it's the games themselves.