Factory reset will not fix a broken earjack. It comes with left speaker, power and volume button as assembly set.
It't not difficult to change as you only need to remover the rear cover and one screw to take out the whole speaker set. Sending for repair is not necessary as it takes at least 7-10 days to get it fix for a simple repair
Loud Speaker Ringer Power Volume Flex for Samsung Galaxy Tab Pro 10 1 T520 | eBay
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This video for replace battery, but just look to see how it's easy to replace the left speaker which is not in the video.
When the back is facing you, left speaker will be on the right.
Important note: the rear cover should be opened from the front , remove from the back like this video might damage some plastic locking tabs and the rear cover will not close as before.This mistake many people do like the guy who makes this video.
https://www.youtube.com/watch?v=wqtYKR6ODw4
This video shows how to put back the rear cover, this guy is clumsy too but I cannot find a better video. See this video you should know the rear cover should be removed by prying from the front, not from the back.
https://www.youtube.com/watch?v=5sw0OxqUzkI