Same problem protect keeps flashing

kenwood has an internal protection feature that stops the output of the speaker channels if there is a shorted wire or bad speaker. this happens for many reasons and is not always serious problem. you can reset the unit by pushing the reset button with the tip of a pin while the until is on. it is a very small black circle located somewhere on the front of the faceplate. it should go back to normal operation after rebooting. if the protect comes back, you need to take it to your nearst shop to have them troubleshoot your speakers and connection.

hope this helps