7510 swicth no longer working Lenar

[Mymnte]

Had power loss and switch was stuck with orange system light and none of the AP's were powered on. I did a factory reset and finally the lights turned green and i tried recovery but after reboot it boots up and while connected using putty it gets stuck at the end and very fast just repeats Please enter login name, please enter password, user login fail,  press enter key to login, User access verification. It does this very fast over and over infinitely. I tried another factory reset and get the same thing. What can i do from here? I tried pressing "b" over and over while booting to reset password but that did not work either. Please let me know, thanks