First, start with the basics. Check if the amp or PA you are plugged into is turned on. If using a mixer, make sure it's not muted and that all cords are plugged in all the way.

Is the amp/cable working with other guitars? Always make sure your amp is working and the cables are in good working condition. If possible, plug in another guitar to the same line to see if it works. If you don't have another guitar, plug a cable into the amp and turn the volume up slightly. Touching the end of the cable with your finger should make a loud hum noise. This tells you the amp and cable are both working. Remember: Keep the volume low for this type of test.

Do you have new batteries in the guitar? If you have a 9v powered Expression System, an ES-T or ES-N system, there will be a red battery indicator light inside the guitar. It's mounted on the edge of the preamp and should light up when a cable is plugged into the guitar. If the light doesn't come on, chances are you have a dead battery or the battery is installed backwards. Look closely at the battery holder to make sure you line up the small + tab with the small notch on the holder. Older version of the Expression System take 2 AA batteries. If only one battery comes out, the second battery may be stuck inside. Do your best to get it out by shaking the guitar or grabbing the tip with needle nose pliers. Always use two brand new batteries and put them in flat end first. Important: Don't mix new and old batteries together. The old one will heat up and may leak acid, causing damage to the battery housing.

You've checked the amp, cables, and batteries and the ES indicator light is on, but there is still no sound. If you have a 9v-powered Expression System, an ES-T or ES-N system, there's one more thing you can try on your own. The ES2, ES-T and ES-N have a small phase switch right near the battery light. If the switch is stuck in mid travel, it can kill the output. Reach into the soundhole and flip the switch to one end or the other and try again.