LED will not turn off with pot

[wingnut]

Hi all

Can someone please tell me why the LED does not dim completely when the sweeper is fully at ground. Thanks.

My apologies, its dimming completely now. I think the ground of the pot was not making contact.

 

[Harald Kapp]

A potentiometer is not a good way to control the brightness of a LED. A potentiometer is not designed for comparatively high currents as required for a LED. Use the potentiometer instead to control a transistor which drives the LED current.
A modern way of controlling LED brightness is by using PWM. Much less power dissipation at the cost of higher parts count.