Since you've taken the motherboard out, you should put it all back together. Then make guide on removing motherboard. Did you take batteries out when trying to unstick button? Eric has good point about contact cleaner. I started using custom configurations for camera action. Turning off the half press to start auto focus and instead I use AF-ON button on back to start Auto Focus. Makes it faster and easier to use. Then you are all ways depressing shutter button all the way. So no sticky gets stuck in middle. Hope you get it worked out. You may find a beaten up 60d and use it for spare parts. Have you tried calling Canon service or local camera shop. A lot of those guys are always willing to talk shop. If you do get info post it please. Good Luck!