Craigslist buyer threatening me?

i recently sold a ps3 to somebody on craigslist which was working PERFECTLY and now they call me after i spent the money saying that it wont read discs, i never gave a guarantee of it working, but now he called me, saying exactly where i went to school and when i graduated and said its a matter of time before he solves this or something like that, im scared shitless, but am i legally obliged to pay him back if it was working before i sold it?