Scroll wheel and buttons stopped working after I opened it up to check sautering.

If you have a generalized scrollwheel problem, i.e., your “music mode ‘play all’” is not the only time you see the problem, and it’s one where you can’t get the scrollwheel to move (as opposed to the wheel moving but the software not responding), then spraying the scrollwheel with electronic contact cleaner might help.  That has worked several times for me when I had a sticky, recalcitrant scrollwheel.  I spray it generously right onto the face of the player, then work the wheel free.