Error: Missing connection between items


I have this error:

Error: Missing connection between items
Zone [GND] on F.Cu
Zone [GND] on B.Cu

How on earth am I supposed to figure out where this missing connection is? The zones are supposed to remove unconnected islands, but I suspect there’s a pad somewhere connected to one of these islands.

This is a pretty complicated board, especially with the zone fill on the front layer.

Is there any way to figure out where the connection is missing, besides stepping through the board inch by inch?

This really needs to be fixed.

I found it, it was indeed a pad that was connected to a zone, but not connected to the rest of GND.

It seems silly that I had to comb through the board bit by bit to find it by eye. I don’t see why it can’t show me the little zone or pad that’s not connected. Or at least a ratsnest line so I can see it.

Can you attach here the board file in the state where it shows this problem? Even though you found it, this may be a good example for possible enhancement.

My employer wouldn’t like that but I can probably make a new one. All that’s needed is an island containing a pad connected to the zone net. Kicad zooms to the whole zone instead of the pad or disconnected bit, so you have to search by eye for the missing connection.

Very difficult with a complicated board.

Maybe if the pad wasn’t considered connected to the net unless the zone it’s connected to is not an island. Then zooming in the drc checker would work.

Some changes has been made in 6.99, but because situations vary wildly it’s impossible to find a simple solution which would always work better.

In this case creating a simplified example isn’t necessarily useful because the difficulties for the end user depend on many things case by case basis.

You can try KiCad 6.99 on a copy of the project to see if this is better now.

I think it would be really cool if KiCad would have a function where it would only display a single net that you could select (maybe dim everything else) where each island of that net would be displayed in a different color. This function could be automatically started when selecting the appropriate DRC message.

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Here’s a previous thread about a similar problem: (Wrong?) error: Missing connection between items - #42 by paulvdh. Suspiciously the test by Paul looks similar to what you describe, with the recent fix in 6.99. As far as I have understood, in v6.0 KiCad wants to tell about pads, not zone areas.

Thanks! Will this screen shot suffice?

If I put a via in that island, of course the error goes away.

Oddly, I tried to reproduce this without success:

This is good behavior. I wonder what the difference is?

If the selection filter had a checkbox for ratsnest lines, that would probably do the trick.

It’s difficult to deduce anything from that. It could help more if you can simplify the design to a level where it doesn’t reveal too much confidential information but still shows the problem unambigously.

Not the selection filter, but the Objects tab of Appearance panel. Or from the left hand toolbar.

Jr22, if you check that the ratsnest lines are visible and hide all layers in Appearance → Layers, do you see anything which could be a ratsnest line?

OK, I’ll try. It’s a pretty complex project with 10 sheets, but I can try deleting a bunch of stuff and see if the error persists.

What’s particularly odd though is that it’s complaining about not connecting the bottom fill to the top fill. It’s not complaining about the isolated fill, or the unconnected pad. So there’s no reason it should show a rats nest line. (They are turned on)

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