If this problem is occurring with battery power, try changing the batteries and turning the power back on using this guide. If it is with AC power, make sure the cable is properly plugged into the wall and the speaker. If neither of these work, the power connector on the back of the speaker may be damaged and needs to be replaced. Check the troubleshooting page if there is still trouble: Altec Lansing inMotion iM9 Troubleshooting