GE MEDICAL SYSTEMS 
D
IRECTION 2392751-100, REVISION 3VIVID™ 4 SERVICE MANUAL
Chapter 8 - Replacement Procedures  8-31
8-3-6-4 Rotary Knob Installation Procedure
1) Using a new rotary knob, insert the metal tension plate (removed in step 4 above) into the centre of 
the knob, aligning the plate correctly with the notches on each side of the hole. The plate, which is 
slightly curved (to provide tension), should be positioned with the curved surface facing towards the 
center of the hole, as shown in Figure 8-29 below.
Figure 8-29 Tension Plate Fitted in Centre of Knob
2) Carefully place the new rotary knob into position on the securing pin, taking care that the tension 
plate remains in position inside the knob, while aligning the core of the knob base with the flat-sided 
notch on the securing pin - see Figure 8-29, above.
NOTE: The notch must be aligned correctly, otherwise the rotary knob will not sit at the correct height on the 
external keyboard.
3.) Gently push the rotary knob down until it snaps into position.
Metal tension plate
Securing pin