Discrepancy:Schematic vs PCB layout

Noob here.
After much head banging, I do not understand why the barrel jack connector pins as shown on the PCB, do not match the net connections as shown on the schematic. Appreciate help/advice. J1 is standard barrel jack with switch from built in library, U2 is a 4 terminal voltage regulator board (Adafruit) which I added symbol and footprint for (without issue, so it seems to me).

OK, so I can’t upload another photo (!?) but on the PCB editor, Pin2 is labeled as Net U2 Vin_6_21V, and Pin1 is labeled Net (U1-Gnd). No clue why this should be. Thanks all!

Hi , beeing a noob myself :slight_smile: You can always reply to your own posting and add additional picture.
Looking at your schematic, not sure how U2 is defined as a symbol, it might be the cause. If you have problems to create a symbol, try find something with 4 pins that you can temporarely use, maybe justa simple 4-pin connector as a start. The footprint does not need to be correct for you to find out what the root cause is.

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About the net names, the name “Net U2 Vin_6_21V” appears to be correct (although I would have expected: “Net-(U2-Vin_6-12)” KiCad uses net names derived from pin names to automatically create net names for all nets without explicit labels. The GND net is weird though. The GND symbol works as a global label and the net connected to it should just have the GND name.

OP here…posting reply containing the PCB picture (thank you Mr_Simpleton).

OP here one more time…I apologize about the extra posts…but I just noticed this also, when I try to update the PCB:

Processing symbol ‘J1:’.
Processing symbol ‘U1:SeeedRelayBoard:SeeedXiao14P-2.54-21X17.8MM’.
Processing symbol ‘U2:SeeedRelayBoard:Adafruit_5V_module’.
Processing symbol ‘U3:SeeedRelayBoard:RelayModule’.
Error: Cannot add J1 (no footprint assigned).

The last error also seems odd, because the footprint is there, and that’s straight from the library…not modified. So unclear what is going on.

I have changed all the ground pin labels to GND, but that did not change anything materially.

Thanks in advance.

Open the symbol’s properties from the schematic and see what’s in the Footprint field.

I wonder where from is the J1 connector at PCB:
Did previously when you updated PCB it was placed there based on footprint assigned to symbol and next time the same symbol has no footprint assigned? Seems unlikely.
So how it happened that J1 footprint is there.
It looks that J1 at PCB has nothing common with J1 at schematic including not pin connections as those at schematic.
The best in such cases is to attach full project zipped then others can verify what is going on much easier than from screen-shots. I don’t know when new user can do it but probably not a lot time spend at forum is enough.

This is where your problem start:

In KiCad, the schematic is the root of your project. It holds the whole netlist (implicitly defined by the wires and buses drawn) it has all the schematic symbols and links to the footprints. You have to assign footprints to your schematic symbols for all (generic) schematic symbols that do not have a footprint, and then you can put them on the PCB with Schematic Editor / Tools / Update PCB from Schematic [F8].

Normally KiCad uses (invisible) UUID’s to connect schematic symbols with PCB footprints. You can override this during the [F8] process, but it is not (and should not) be the default method.

That helped. Although I did have the correct footprint for the jack, it did not seem to be associated with the symbol properly. Opening the symbol’s properties, finding the footprint, and then double clicking on it seems to have done the trick! Many thanks!

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