I had the exact same thing happen to my R3 131T! I don't know if this is still happening now, but if anything someone else who has the problem can now find the answer on this thread. I tried everthing else on here and it didn't work. All you need to do is turn it off, press the battery reset pin hole ( I held it down for ten seconds), wait a couple minutes and restart and it's working again! The acer support suggested it and I didn't think it would work but it did! Extra note: I did have the audio disabled. if you go into Device Manager (right click on start button) you find the sound folder, highlight real tech, the diable button is on the top toolbar thing. 
Hope this helps!!