You made sure all your wires are in the right place, and aren't mixed up on the chip? (I remember that stinging me with an Infinity once, lol
)
Otherwise, all I recommend you do is go over your BIOS points and check they all correspond to the diagram and on the chip itself, and check all your points with a multimeter from the chip pad to the next component along the trace from the solder point to ensure you have a good connection and continuity
Good luck!