I have a problem with an external keyboard: when its connected for the first time it is recognized and works normally, however after some time (1/2 hour to several hours) it stops being recognized and the usb port stops working; if another device is inserted in the otg it would not be recognized either; connecting/disconnecting to the otg would not help. The only remedy in this situation is to disconnect the otg cable from the tablet itself and connect again, after this the keyboard and the port would be working. My systems version is 4.2.2 and it has settings for external keyboard but manipulating them doesnt help. What kind of problem is that, is it the fault of usb port, otg cable or android?