I have a Harlem Globetrotters that always has a faint "white noise" sort of sound, sounds just like when the TV station went off the air at night (if any of you are old enough to remember that). All of the regular game sounds are there, there's just a noticeable static-like background noise. It starts immediately when the game is turned on and never changes, although it will get louder / softer if the volume is turned up / down. Grounds are all good, connectors are good, all new caps on the sound board. Any ideas?