Use a Phillips-head screwdriver to remove the back panel of the amp. Check the wiring for any frays or breaks. If any of the wires is frayed or broken, it needs to be replaced before you can continue using the amp. If any wires are bent, use a pair of needle-nose pliers to bend them carefully back into place.
Check the soldering on the wires. If any of the soldering has come apart, sound quality and performance will be affected. You can solder the connections back into place or have it done professionally.
Use a can of air to clean the controls and the speakers. Dust can interfere with electrical connections and prevent the amp from working properly. Cleaning dust out of the amp's controls and speakers will help the electricity complete a circuit, giving you better sound quality.
Move the amp away from any other electronic devices, such as your television, cellular phone and video game consoles. Other devices can interfere with the amp and cause feedback. Keep the amp at least ten feet away from electronics to ensure better performance and sound quality.