The Lenovo Tab 2 A8, model A8-50, is an Android-based tablet released in April 2014. You may see model A5500-F in fine print on the back (distinct from earlier A5500 model)
It could be possible that some of the components inside your phone have slipped apart and you need to open you phone and put them together. I dropped my phone and once I took a look they had been separated. I put them together and the icon reappeared. Hope this helps.
