The amplifier is overheated. The speaker wires are shorted. The ground wire is open.
The speaker's impedance is above or below the rated output impedance.
The Amplifier's overload protection circuit automatically shuts down when any one of the above conditions occurs. If this happens, turn off your sound system and let the amplifier cool down before you restart.
LISTENING SAFELY
To protect your hearing, follow these guidelines:
Do not listen at extremely high volume levels. Extended, high volume listening can lead to permanent hearing loss.
Always start by setting the volume to the lowest level possible before you begin listening then gradually increase the volume as necessary.
Once you set the volume, do not increase it. Over a period of time, your ears adapt to the volume level, so a volume level that does not cause discomfort might still damage your hearing.
