Your player may be reading the memory of the external card in the CARD ONLY mode. To switch to the BOTH MEM mode. First make sure that you are in the VOICE or MUSIC mode, press the right ··· key to enter the menu use the UP/DOWN key to select MEMORY, press the PLAY/PAUSE key to confirm. Use the UP/DOWN key to select MODE. Press PLAY/PAUSE to confirm. Use the UP/DOWN key to select BOTH MEM.
You may have stored your music files in folders on the player. Please make sure that all music files are located in the root directory only of the Removable Drive (RUSH).