Quote Originally Posted by badrad
So, I am not totally alone with my problems...
Did you rework your design or shield your PIC?

As for my problem, since then, I had to rework my pcb and included the following:
1. left the unused pins alone, but defined them as outputs. (now this might sound contrary and I did initially ground them and assign as inputs, but the tech people at Microchip recommended this to me).
2. put in sufficient ground plane.
3. installed MOV at my A/D input as well as at the power input.
4. increased my A/D input resistor from 1K to 20K.
5. keep my fingers crossed...

All my PICs have been the 16F876A I/SP.
Hi badrad

Well yes I did re-design board again and, I kept unused pin as still input, but I take care
Ground plane very beginning but my mistake was I did not set unused pin as input and tide pins to ground, additionally I improve power supply for reduce ripple noise and more proper casing design.

Well so far 11 months I do not have any problem but who knows what it comes next

Theory for all of us engineers or beginners some time we have iron wall front of us due of undocumented information’s or poor documentations. That’s the reason why we have to keep researching for tomorrow.

Regards

Joe