The fuse only protects against pulling more than 10A at the input. That's 120W+ ... more than enough to create fireworks if something goes wrong internally or something gets shorted out.
I believe the part you're talking about is Q2 (8 pins). It's FDS9435A. It appears to be used as the load switch for one of the power rails.
It might help us to understand what happened if you can show us a picture of your supply. Also, which yellow wire did you find loose and where did you "plug it back in?" My assumption here is that you somehow either shorted or crossed two of the supply rails. This caused an excess current to flow through the Q7 switch and release the magic blue smoke.