RE: 977 fan bearing???
I have the exact same problem with a charger that is several years old. Sometimes the fan doesn't start at all but if I bump the charger or blow on the fan then it starts. Other times it will be running fine but then if I move the charger slightly it will start making a crazy buzzing sound and the fan speed slows down a bit. Not sure what the issue is. I've had mine apart but couldn't figure out anything. The fan is very simple so I'm not sure if it could be repaired or would just need to be replaced.