turn volume up key stuck pressing down but volume down key works fine

Joshua Crowell it is possible that this is the switch itself. Post some good pictures of your board (both sides) with your question. That way we can see what you see. You will need an ohmmeter to check the function of the switch. It should be open until depressed which then closes it for the time it was pressed. Once we have a picture we can probably guide you a bit better. Sandisk Sansa m230 Series mp3 player Teardown

Based on your images the one button (under the crystal cans, the right one closer to the USB port) seems to be broken. At least the 'plunger' bit is. It could be that when it broke a piece of it jammed the button down, and now that its been taken apart the piece has cleared. Try reassembly and see if the always down condition is fixed. Of course now the problem is whether or not the plastic bit of the casing button will reach the PCB button to turn it up. If not you could super glue something onto it to the normal length. Or just replace the whole button supposing you can source one (take measurements and try digikeys parametric search) and your soldering skills are up to the task.