I have been told that this is because no current is being drawn. The ball bearing and or/spring can then be heard rattling about. We hope that you understand.

Brand: Hornby
Assembly Status: Ready to Go/Pre-built
Type: Controller
Model: Live Steam Controller
Scale: 1:76
MPN: R8205 X5040
Control System: Analogue
Country/Region of Manufacture: China
Compatible Control System: Live Steam
Colour: Multicoloured
Gauge: OO