Motorola Xoom :: Internal Speakers Muted?

Mi Xoom has stopped playing any sound through the internal speakers. They worked fine in the beginning, but a week ago they were muted for games, video and music. However, i do get the sound through headphones.The speakers are not broken, as i get notification and alarm sounds normally.I tried the factory resetting, but without success...Problem might have come up when i tried headphones for the first time or when downloading some volume control app -unfortunately i cannot say precisely when the problem occurred.