Firstly, play the music on a different device and check if the music file is actually corrupted. If the file is good, then your speakers might have a bad connection or they might have worn out. Open the casing, revealing the speaker ports and ensure appropriate connections. Play music file and if problem still persists, then replace your speakers. Check the Kindle Touch troubleshooting page for options.
When you dropped it, you might have disconnected the WiFi antenna cable. You will have to open the casing to reveal the entire motherboard and on the rear side top left corner, there should be a black antenna cable that is unplugged. Just plug it back in by pushing it down into the port. If that is not the case, then you will have to replace the whole motherboard. Check with the Kindle Touch troubleshooting guide for options.
There is a possibility that your cable might not be working so try checking it on a different device. If the cable works then it might be a bad battery or a bad USB port. Check the troubleshooting page for more info on that.