Guys,
the servo is the digital mini and is whining when under no load (ie no arm attached to the servo and no control surfaces). Its not really annoying but I've never heard a servo do that before! I'm taking into the shop 2moro and I'll see what the owner says, and have a look at some other 5245's. I'll also see if moving the trim reduces the whine. Thanks for your replies..........
Andy