You can fix it yourself but you will need confidence to do it - given that you need to ask here it's possible that you do not have the confidence.
You biggest challenge will be to open the case without damaging it.
When you plug the headphone jack into the device a simple switch disconnects the main speaker - it would be silly to have the speaker playing at the same time as you listen through phones.
Examine the mechanism of the connections of the jack socket. Use a toothpick to force the speaker connection to close - then you'll know. Carefully bend it back into place.
Speakers seldom if ever fail - your speaker is likely to be good.
Good Luck..., July 2016
