This is a list of all the things that you can change from the "settings" menu option. In the EQ selection, you can change equalizer settings. There are some presets, but there is no option to set your own equalizer profile. In the PlaySequence selection, you can set the MP-350 to play files in random order or to repeat some or all of them.
For reference reasons, we post the following pictures to demonstrate the various settings.
The MP-350 uses a "happy face" screen saver, which is a small yellow face bouncing from one corner to the other. Additionally, leaving the player idle for a short period of time will shut down the screen, and if it is not working at all, it will automatically shut itself down to conserve battery power.