Bear with me on this, I'm asking on behalf of my mother, who's Rev. A mac mini is having issues. She says that she had her computer on and the power went out for a few minutes. After the power came back on, she said that her computer booted up fine, but she cannot login. I tried talking her through a safe mode boot and a PRAM reset (but I'm not even sure if she did those properly, to be honest), and no dice on either option. Does anybody have any sort of ideas on what I can tell her to try? On all occasions there was no delay during the bootup process.