apple tv signing in problems

i have not used my apple tv for a while, it is a 3rd generation, i tried to use today and it asked for apple id password, i entered correctly twice and then said i needed to retrieve it as it was wrong

i changed it on itunes and it works with all my devices, but when i try on apple tv it says either cant find apple id or password incorrect, i have also reset the device twice to no avail

any ideas?