Do check the cables - as has been said
Download Goddisk - boot disk with many many CD drivers (but I'm too lazy to look it up - google it, if you can't find it PM me and I'll stop being lazy)
Check the power connection for the the CD in the box - if it does light up on boot up, then stick a CD in and boot with a boot disk. Go to the D: drive (or whatever letter the CD drive is) and just do a DIR. If it reads it, then load all the drivers on Goddisk and you should be ok.
If it doesn't read it, you gotta check the hardware. Get an airduster, open it and clean inside. Then start again...