HI When I press in High Pass Filter button to engage I get loud popping noise in my speakers It does not happen when I press Low Pass Filter Button Why would it do this Help Randy
No way to tell without tearing into the unit. Most switches are now sealed from the environment. It's difficult to simply flood the control with tuner cleaner and solve a problem. And you risk flooding the circuit more than the switch if you just begin spraying cleaner without any idea how to actual clean a switch.
Have a tech look at the unit. Ask for an estimate of repair cost before proceeding with any work.