my mac mini will not read any disk, it thinks about it then spits them out.

I am completely frustrated! I thought my disk reader was malfunctioning over a cd with family pictures on it. But now I realize that my mac mini is not reading any disk. I don't use it for movies and things, but have recieved a digital copy and am now experiancing the same thing! It takes the disk, spins and sounds as if it is doing something for a minute or two then ejects every disk. I have tried multiple cd's,dvds and disks. I'm out of my warranty date, but seriously don't think I was ever able to use it! Bought brand new from an Apple store.

I have shut it down, unplugged cords, pressed option, command P and R

done everything that the internet has said to do, PLEASE help!

Thanks in advance! If you need more info please repond.

Info:

Mac mini

Model Identifier:Macmini4,1

Processor Name:Intel Core 2 Duo

Processor Speed:2.4 GHz

Number Of Processors:1

Total Number Of Cores:2

L2 Cache:3 MB

Memory:2 GB

Bus Speed:1.07 GHz

Boot ROM Version:MM41.0042.B00

SMC Version (system):1.65f2