My iPad has no sound
My iPad has no sound. Already tried rebooting and resetting (not to factory setting) but still it has no sound. Although alarm could be heard. Sometimes the sound appeared seconds after the iPad is switched ON and sometimes the sound appeared randomly when using the iPad. What's more, the volume bar (the thing that is use to increase/decrease the volume on screen) is gone! Neither when using the volume changer (beside the iPad) nor on control centre (so it is left blank). There is sound when using headphone but if it's left switched OFF, it did not produce any sound, so I had to unplug and unplug it back. This problem came before iOS 7 probably during iOS 6.0.0+. So any suggestion? Should I buy a new one?
iPad 2 Wi-Fi, iOS 7.0.3