Sticky stuff on the board? Did you clean each cap area after removing the caps and before putting in the new cap and solder it?

If yes, then thats just Rosin Flux from the solder, which can be hard to remove but alcohol and/or acetone can be used with some hard rubbing to remove it. I use alcohol for Rosin, and a lot of cotton balls and q-tips. But Rosin should not effect now the machine boots. Its non-conductive when its a solid and only help for solder to cling to a metal surface when in its liquid state.