mobile

Ok so here is the story. Before last week friday, I havent used my nexus in a year because I had no idea what was wrong with device that wouldnt let me charge. Then one day home from spring break I looked at it and figured it out and I ordered the part. I fixed it on Friday and it was working and everything! I was on it all day Friday and Saturday and half of Sunday. Then late that Sunday evening, I was going to listen to music then it started freezing up. I was trying to skip songs but had a slow reaction to it. The battery was on 60% so it shouldnt be the battery. Then the tablet shut off and never turned back on. I even charged it the whole night and nothing. I plugged it into the computer and get APX mode. Ever since Monday morning, I have been looking for solutions and I believe none were really successful. I did manage to change driver to Android Composite ADB Interface or something like that. Can anyone offer any other solutions please? It just doesnt make since that I was using the tablet then shut off all of a sudden. And I know it is charging because I can feel the heat from the Nexus.