mac mini flashing black and white after attempted reformat.

[slothhh]

i was trying to reformat my old mac mini, because i had lost the password and before i could reformat, it asked me for my password, when the dialogue came up, i click on details, and chose the second option down which i think was 'mac OSx installation disc 1'. my computer shut down, and now when i try to turn it on is flashing black and white every about 30 seconds.

 

[BlueRevolution]

Have you tried booting while holding the C key?