This Crown Com-Tech 400 two-channel power amplifier has some minor issues. One of the rack ears at the back is bent, and the screws and holder for the grille foam at the front are missing. Despite these issues, it still offers great performance for your audio needs.

To use this Crown Com - Tech 400 power amplifier, first connect your audio source to the appropriate input channels. Then, connect your speakers to the output terminals. Make sure all connections are secure. When you turn it on, adjust the volume and other settings according to your preference. Regarding the bent rack ear, be careful when mounting it to avoid further damage. Since the screws and holder for the grille foam are missing, you can either replace them or use the amplifier without the foam. For maintenance, keep it in a clean and dry place. Regularly check the connections and clean the exterior with a soft cloth. If you notice any strange noises or malfunctions, turn it off immediately and seek professional help.