Some possible problems to look for:

- Incorrect pinouts on the cable that connects it to the player.

- Loose wires on the player's docking sled.

- Problems with the antenna connector (either inside the box or on the connector). Try opening the box and soldering some antenna wire directly to it to see if that gets a signal.

- Chips plugged in or soldered in upside-down during the assembly process.

- Other assembly errors such as gaps bridged with solder.