L293D and SN754410 will not interchange

I am using the instructibles motor shield from


I am using it to run a thin gear box for use as a line follower/sumobot. The l293 were getting a little to hot during operation so I figured I would switch to the sn754410 that is suppose to have the same pin pattern. When the sn754410 is in the circuit nothing happens. I tried several chips all with the same outcome. The L293 always work. What would I have to do to the instructibles circuit to make it work with the sn754410?

Make sure they're in the right way? They should be interchangeable. Pinouts and specs are the same between them.

definitely in the right way