Try and get the A/V cables(red yellow white) and connect them to a regular TV. If you can't get your PS3 hooked up to a TV, you can't reset it. There is no hardware reset button on it.
Thanks i own you one And i found the reset which i really didn't need but you press the Power button for 5 sec until it beeps 2 times thats how u reset the settings for graphic i think