The trick with DIN connectors was to try to insert them gently while rotating them. Once you got the notch lined up they would very clearly drop into the socket at which point you could apply more pressure to fully seat them. It was only a problem if you were jamming them in full force while rotating because you could exert enough pressure to force it into the socket even with the key notch misaligned crushing the pins. I never once had a problem inserting a DIN connector, something I absolutely can't say about USB-A.