Do you still have your original PCB? Switching round and trying that would help rule out whether it's a mechanical failure or hardware failure.
Nonetheless, you see where the white, green and yellow wire go into near the motor? Check on the other side of that, as that is where a tiny lever is which tells the drive whether it's open or closed - if this has somehow become jammed then it will explain your problem. I had a drive which would never close and it turned out that lever had become damaged somehow and would never flick over properly, it's worth an inspection.