I used a power supply that was rated at 12VDC 1.0MA. The unit I was using needed 12VDC 500MA. When I plugged it in the unit buzzed when I turned it on. The light didn't illuminate on the switch, however it made that strange buzzing noise. I felt like I was causing damage to it so I turned it off and unplugged it. I went back to it later on and tried plugging in headphones and a drum pad. I used the same power supply thinking maybe that was a normal thing for the unit to do without having a pad plugged into it. (It's pretty old) so I turned it back on but this time the buzzing was gone, and instead I heard it through the headphones instead of the unit itself. I even tried out a brand new power supply that met all its requirements. I'm scared the unit is broken, but I can't see how it is because I'm using the same voltage, etc. does anyone have any idea about this?
