Hey. Lately my Galaxy s2 is going mad. After being charged overnight and having the 100% thing, i turn him on and he seems to work fine. However after a short time (depends if i'm using it or if hes in 'sleeping mode', but eventually it happens) it just shuts himself off. When he does that i cant turn him on again, getting the Galaxy s2 screen then the Hello one and he shuts off again. The only was to turn him on again is to connect him to a charger. Also, if I'm using him WHILE he is connected to the charger, it will NEVER turn off no matter what. Before he shuts off, the screen is blinking(seems like the brightness changes from 100 to 0 rapidly but I'm not sure), i get a no entry sign on the top-right of the screen and then he shuts down. I had this problem for a few weeks now,been trying to solve it with google but everything failed so PLEASE help me with it!