# PIC18 not working when wiring 30pf capacitors of cristal resonator to ground

I'm using pic18 with external oscillator 16MHZ 16M HZ HC-49S Crystal Oscillator with two 30PF capacitors

configuration OSC = HS

using breadboard, when wiring the capacitors to ground the pic stop working, but when letting them in open circuit (just wire one side to PIC, other side stay open) the PIC work again.

but when removing the capacitors from the circuit, the PIC also not working

what explanation for this

• There is probably enough picofarads in the breadboard to make it work, but when you add an extra 30pF it becomes too high a load? Oct 29, 2014 at 7:06
• @KyranF can the breadboard behave like a capacitor???? Oct 29, 2014 at 7:08
• Yes, indeed. with Picofarad magnitude! The pins in the breadboard capacitively couple to nearby pins. You really should not try to use 16MHz signals on a breadboard, it will hardly work even if you think it is. Oct 29, 2014 at 7:14
• Good old Dave Jones (a fellow Aussie!!) talks about it in his video maybe that will help you understand it: youtu.be/6GIscUsnlM0 Oct 29, 2014 at 7:15
• Yes, those white solderless breadboards have a significant amount of capacitance and inductance... more than a PCB. Oct 29, 2014 at 7:15