Quote Originally Posted by Christopher4187 View Post
Hi,

For the power supply (3V) for the PIC, I am going from a voltage divider, to a regulator with a filter then to the PIC. For the digital inputs, they are going from the voltage divider directly into the PIC. I guess I am not sure if the input for the buzzer is causing the PIC to reset or if the buzzer is somehow feeding back into the regulator, which is causing it to reset.
Like Jerson said, a schematic would really help.

A big cap at the buzzer might help... but.

1- 3 volt regulator fed from voltage divider. Input voltage I would guess is higher than 5 volts?
2- Voltage divider directly feeding inputs. What is this voltage?
3- If the divider is set for 5 output with 74 input a spike would over volt the inputs, and if 5 volts is enough to run the regulator, a voltage drop would also drop the regulator out.

Try not connecting the inputs of the PIC. What happens? If works when the buzzer is on try clamping the inputs.