Xbox 360 cannot read xbox 360 games.

Question

i bought the xbox about 1 1/2 years ago. within a few months of buying the xbox 360, i had to send it in to be repaired due to the "three red ring virus". since receiving it back, it's not worked great. now when you insert a game in it, new and old, it says unable to read disc, please insert into a 360 console.