I purchased a white controller from Amazon when Smashboards was having the deal for $20 a while back, and I've been having some errors from time to time.
When I try and play Melee, sometimes I'm not able to get the inputs I make. For example, I press the A button to do a FAir, but it doesn't register the A button, causing me to do an empty jump. Or if I try with the C-Stick, sometimes it doesn't register that either. When I try to wave dash, it gives me empty jumps, or it ignores my jump button and causes me to spot dodge and get punished. Also, when I try and dash dance, my control stick ignores one of the directions and will only have me dash in one direction. Lastly, when I try to pivot grab, it doesn't give me the pivot (but that could just be me).
I have other controllers, but after using this one for so long, the others don't feel as loose as my white controller. Also, does changing the shell of a controller effect button inputs? I'm using the motherboard of my white controller with different front and back shells with the buttons and L/R triggers from the white controller, so I don't know if because it's not in it's original shell, the buttons and sticks don't work as well.
Worse case scenario, I just change motherboards with one of my other controllers and I'll report if it helped my issue or not.