1. Check the status light on the front of the unit:
- If solid, check the volume and audio connection.
- If blinking, ensure that the unit is no longer connected into your computer as the unit will not play while connected.
- Ensure the memory cartridge is not loose.
2. Verify the files are in the .mp3 file format.
3. Unplug the unit and remove the cartridge. Look at the pins to make sure that none have been inadvertenty bent or broken off. Replace, then power back up