playstation reads dvd's but not game discks,how do I rectify this

michael, sounds like a misaligned or dirty laser. Try to clean it with either a store bought DVD lens cleaner or use some isopropyl alcohol to clean it. If that does not work, you can either replace the drive Use this guide this guide to replace your PlayStation 3's Blu-ray disc drive. "Replacing a defective Blu-ray drive with a replacement requires swapping the Blu-ray drive board from the old drive onto the replacement." or try to replace the laser by following this guide. Hope this helps, good luck.