Touchscreen and sim reader both stopped working at same time.

[carpsy151]

I have the ATT sgh-i747. I was using it as normal. The battery was low and i could not charge it before it got to 0%. After it died, I connected the charger and started it back up. When the screen came on the "no sim-emergency calls only" message was there and the touch screen did not work. Also the time and date were off, it said 3:59 September 15th. I tried the normal reset (take battery out, replace, turn back on) several times and still the same thing. I had just replaced the sim reader a month ago, as well as the rear camera and speaker, and everything was working as normal. I opened the phone up to make sure all connections were set. Still the same message. I did a factory reset and after I turn it on, still, the touchscreen does not work and still says no sim. I find it odd that both these things would stop working at the exact same time. Also the phone is long past its warranty. Any ideas on what this could be?