Can anyone tell me why my 16c84 is making a buzzing noise. I am a novice
and this is my first project. It is a very simple gate controller that
checks 6 inputs to see if the gates are closed. If a gate is open it takes
that bit high to switch a led on.

The controller works well but makes an irrataing buzzing/whinning noise.
Any ideas??

Thanks in advance.

Andy Parry
Durban
South Africa..