O.K. I've got a Yamaha BBN5II which has two big soapbar pups on it. It's passive. When both pups are turned up full, this is one of the quietest bass you'll find. Now suddenly they hum all the time. When both pups were up full, if you turned one of them down a little you'd get a very slight, tolerable hum. Now it seems that only the bridge pup is working O.K. If you solo the neck pup, you can hear that the B, E and A strings aren't putting out as strong a signal as the D and G strings. This is verified by the gain light on my amp. So, could something have come loose? No one has dropped or fooled around with it. I took the back cover off to take a look, and everything seemed O.K. I'm moderately mechanically inclined, do I have to take this thing apart. If so, what do I look for. This bass was only $400.00, but, I love the sound. Is this the price you pay for paying a low price? Any help would be appreciated. BTW, if you solo the bridge pup, it's got full power, and just a slight hum. Also, I think the pups are split P-bass style with one half handling the B, E and A strings, the other the D and G. Thanks, Mike J.