Radio hum, 1988 Bose Radio

[ejball]

I have lived with an intermittent hum in the radio for years now. When I'm driving I hit a bump and the hum appears, then I may hit another bump and it goes away. I can usually get rid of it by just turning powere off and on again. Lately though, it has occurred more often and I am going to start to trouble shoot it. It appears in all speakers so I believe it is either in the radio, power or ground to radio, possibly diode on alternator, or maybe just a filter required on power supply line. The hum increases with RPM so it is tied to the alternator, but I can make it go away usually by cycling the radio power.

If anyone has had a similiar problem, please let me know what you found as a solution as it may save a lot of trouble shooting time. The help is always appreciated.

 

[sriat]

I have lived with an intermittent hum in the radio for years now. When I'm driving I hit a bump and the hum appears, then I may hit another bump and it goes away. I can usually get rid of it by just turning powere off and on again. Lately though, it has occurred more often and I am going to start to trouble shoot it. It appears in all speakers so I believe it is either in the radio, power or ground to radio, possibly diode on alternator, or maybe just a filter required on power supply line. The hum increases with RPM so it is tied to the alternator, but I can make it go away usually by cycling the radio power.

If anyone has had a similiar problem, please let me know what you found as a solution as it may save a lot of trouble shooting time. The help is always appreciated.

Due to each speaker having its own amplifier. The head unit must be the common problem. I would bet there is a loose connection within. The soder within is a continual problem.

Start there.