You read 12V at the fuse? Which side of the fuse? Measure for voltage across it: - on one side, + on the other, and you should see awful close to zero volts. If you see anything other than zero volts, the fuse is blown.
Did you check for voltage at the 3.3V output? Measure for 3.3V across C286, for 12V across C165, and for 1.05V across C288.