Quote Originally Posted by Pic_User View Post
Hi Techbuilder,

1) Do you have a resistor pull-up on PIC MCLR to Vdd (+)?

2) Are you using a PIC16F84 (as written in the code) or a 16F84A (as listed in your programmer jpg)?
There is a big difference between the PIC16F84 and the PIC16F84A to the compiler, software, and programmer.

3) You should have a capacitor at the input to the regulator if the unregulated filter capacitor is over three inches away from it.

4) Do you have a 4 MHz crystal with capacitors to ground or a ceramic resonator with center tap to ground on the osc pins?

-Adam-

A capacitor between the output of the regulator and ground is *very* important to stop the device oscillating at high frequency. Try a value of 100nF.

Andy