Mr. Zager tests electronics during his final inspection and electronics are tested again before shipping so they should be working. With that said sometimes we'll have a bad battery or heat or cold will ruin the battery during shipping. Contact us and we'll send a brand-new replacement battery along with a free gift for the inconvenience. If you already installed a new 9-volt battery and it's still not working, make sure the amplifier cord is fully snapped into the bottom of the guitar. When they're brand new they're tight and need a final snap. Also make sure your amplifier cord is good and working. If you need a new cord let us know and we'll send you one. If you're getting a hum that's a sign of a low battery. If you're getting an uneven sound between strings when plugged in watch the video called "Uneven sound when plugged in". If everything is in order and you're still having an issue, please contact us. This video will guide you on troubleshooting electronics: https://youtu.be/UguEw2NVBlU