I HAVE THE H PRO, AND IT WILL NOT START THE MOTORS UNTIL I HAVE AT LEAST 9 SATELLITES CONNECTED TO THE AIRCRAFT. I ALSO WORK ON SOUND BOARDS. WHEN I HAVE A KNOB OR A FADER THAT SOUNDS CRUNCHY THROUGH THE SPEAKERS, OR NO SOUND AT ALL. I DO THE CONTACT CLEANER TO REMEDY THE PROBLEM. BUT IT USUALLY...