Well I did something stupid, I placed a 4" by 6" photo paper that was cut in half in the upper cassette, thinking that I could save paper and it got stuck in the printer. I managed to take it out piece by piece but I still get that error code 1311 and the printer interface won't let me go to the menu. Maybe the paper sensors are damaged? Maybe there's still some paper stuck that I can't see? Any help would be greatly appreciated.
I took two of the same 4" by 6" photo papers, taped them together to make it 4" by 12". I removed the two back components to expose this white upper cassette paper path thing. I slid and pushed that paper where the red arrow is (see photo) so it come out on the other side underneath the rollers as if it would normally print. Nothing came out with it BUT when I plugged the printer back, the 1311 error message was gone. I decided to print on a normal piece of paper to see if the printer still works and lo and behold, a piece of the original photo paper that was stuck somewhere inside came out with the normal piece of paper. I did the printer maintenance and all tests have passed. Hope this helps.