If it's locked, it's locked for good. You can try to get the Computer Whiz perk, which allows you to hack a computer that was previously locked. If you hack another terminal, I recommend that you hack it up to the third try. If it's not successful by the third try, exit and try again. The terminal will reset with four chances to unlock it.
RIP The Radicals. One is in Heaven, while the other one is in Hell. PSN ID: WWE_beats _TNA
There's nothing you can do unless you get the computer whizz perk as the person above said but If you're willing to take some time unlocking the terminal there is certain characters which knock out some of the dud passwords, you can also reset your attempts using this method on some terminals. You'll notice which ones I mean if you go through each character