last night i bought a used PS3 fat and i bought so...

last night i bought a used PS3 fat and i bought some games for it. when i took it home and put in one of the games it start to act up. i was playing one game and it took forever to load. then i play another game and it was working good a til it just freeze or go back to the PlayStation menu. now the games are fine there's nothing wrong with them it just the game system.