Dvd player reads'' disk not read or no disk''

Question

when i put in a cd or dvd disk it start to read it for about 10 to 20 seconds ,but then states ''disk not read''. I've tried both cd's and dvd's with the same result. I tried changing ''disc recorded'' in: PAL, NTSC AND AUTO, with the same result. ''disk not read''. The only other thing Ive haven't tried is changing regional codes which should be at #1, but I don't know how to find that section on the menu.