My Sansa E280 has garbled sound in playback. The

I have experienced the same problem with my sansa and taken it apart to see what the issue is. It has to do with the connection of the audio port on the board. Its not making a clean connection on mine, wiggling the cord or flexing the board in different ways made it sound right or recreated that crappy garbled sound. I still haven't found out how to permanently fix it, but taking it apart and tweaking mine has helped quite a bit getting it right.
I suggest you crack yours open and try and tweak it, or sell it.
To pop it open, if you haven't already ripped off the front cover. You'll need a very small precision Phillips or flat head(I used a flat head, can't find my Philips) On the bottom right, opposite of the headphone, there is a hole, stick the screw driver in there and remove the rubber cover, then remove the screw behind it. Now there is a locking mechanism behind the screw, you need a needle or paperclip thin enough to fit in the hole. Gab it in hard and then pry the case opfrom the bottom, leaving the top like a hing. There are 6 clips on the inside that will resist the opening, and if you have kept pressure on the paper clip, you won't have broken the anchoring clip by the bottom left. There are 5 other screws that have to be removed to get the board out to look at both sides.
Two screws on the LCD display, one above and one to the right. There are 2 screws on the board. both near the bottom,one on the right and one on the left. and the last screw is hidden in the bottom left corner of the display.
You can remove the battery and the screen if you like. If you remove the screen and reconnect, you may have to do a full shutdown(Hold down the off/on button) and start up of the unit for it to display correctly again.
When you have it all apart, have it play some of your music and prod the jack linkup. Try and figure out what makes it sound awesome and what directions make it sound like ****. Put some pressure on the board and remember what directions of flex make it sound good. Going to a FM station also works, if your headphones don't make a good connection, you can not get reception. Good luck!