How do I get my Xbox 360 to read discs?

My Xbox 360 was working fine last night. Today, my roommate put a disc in and it said “reading” for a while on the screen before going back to just saying “open tray.” We tried several different discs, removing the hard drive, and restarting the console with no success. This Xbox already had the infamous “red ring of death” before Microsoft refurbished it, so this whole situation is quite frustrating and any serious help would be greatly appreciated.