I have a chip that is labeled L293D with a small 'ST' logo, which does not behave like I believe a L239D should:
I have the chip on a breadboard with pins 4,5,12 and 13 connected to the ground rail. The positive rail gets 6V from a battery pack. A motor is connected to pins 3 and 6. Pin 2 is connected to the positive rail.
Now, when I connect pin 1 (enable 1) to the positive rail, the motor spins, which is expected.
The weird thing is that if I connect pin 16 instead of pin 1 to positive, the motor spins, as well.
Also, with the motor connected to 11 and 14, and 15 connected to positive, the motor spins if I connect pin 1 or pin 16 to positive, but not if I connect pin 9 (which should be the enable pin for that side).
Does any of that make sense? Am I missing something here?