Ps3 not reading disk

Question

just brought call of duty..and days later my ps3 is not reading any disk! Read a lot of comments and they have the same problem with the same game(call of duty 4).

Do not buy buy call of duty..that game has to be faulty as it caused too many problems.I have no warranty for my ps3 as i got it from an old mate... iam in a lot of trouble. What can i do? Can someone help me. Please!

how can i reset the setting of my PS3 if i set the setting the monitor is dark