Answer to: iPhone 5s motion sensor doesn't workI just experienced the same symptoms: Replaced the battery, and afterwards none of the sensors worked. After searching more than just the "how to" videos, I found ifixit's step-by-step online guide. I cannot emphasize enough: The four (4) screws securing the RFI shield over the cable connectors are *3* different lengths. The differences are too small to see with the unaided eye. But if you put them in the wrong holes, you can disable the sensors (best case), or damage the logic board (worst case!). Fortunately, I have a set of micrometers, and was able to measure the screw lengths precisely. After disassembling again, measuring each one, and reassembling with the right screws in the right holes, all sensor functions were restored to normal. Hallelujah!
Answer to: iPhone 5 Screen won't rotateExact same problem. Occurred when I replaced the battery using the ifixit kit. Apparently I've broken the phone. DO NOT ATTEMPT A BATTERY REPLACEMENT ON YOUR OWN. Take it to a store where they guarantee the work and pay them to do it. It isn't worth trashing a $400 phone to save $50.