If the servo is under load, the buzzing sound is the servo trying to hold a position. You can stop it by pressing the "Release" button in the server control window, but if you got some weight on it it will cause it to drop.

If you put too much load on them, they will fail and burn out, a tip is to use springs and such to counteract the load and make the job easier on the servos, or buy heavy duty servos that can handle a bigger load

I used the release button each time it happened. There was no load on it at all, I was just testing the servos. It's fine when it's moving right. I tried centering the servo but each time I drag it to the 1 position it still continues to make the buzzing sound. Appriciate your help.

As per the tutorial section and hardware description, every servo model has a different range. The ez-robot servos do not go less than ~10 and more than ~90. Please read the help for controls you are using to ensure you do not damage your servos or ez-b.

The tutorial section is your best friend. There is only so much we can do in code to help. The rest is published to help you. But it does require a bit of reading.

I received my kit last week and all four normal servos were bust out the box. I bought new ones at my local rc shop no problem so I think there is a problem in the factory. I am still waiting on a reply on my thread about it. Was quite disapointing.

I must have watched the clips about 3 times each, and read through all of the literature but I never found anywhere where is says that the servo needs to be set between 10 and 90! I'm sure that its there so I must of missed it. When I was playing with the board last night I did try to set the servo to 10 (I noticed that the buzzing stopped if I did that) but then I couldn't centre the servo properly.
Any tips would be much appreciated!
Thanks for all of your time and help - I'm pretty sure that it's something easy but my simple brain can't work it out!