I have a pro 3. Was using it. Turned my attention away for a while with the volume down. Came back and have no audio from the speaker. Headphones work fine. Squelch and RF gain all set correctly. Checked the external speaker jack to be sure it wasn't funky. Is there some CPU reset command for the audio? BTW restarted it after a cool down---no audio. The service manual refers to an RL351 switch at the speaker controlled by the CPU but I don't see any way to reset or control it. Any help??