Hi there, I have 1 component that shows a ratsnest trace that is connected from the power pin to nothing. Although the pin is shown to be connected to to the power plane, DRC reports it as unconnected. I have tried everything to get rid of it. even if i connect the pin to another VCC pin, the ratsnest trace remains unimpressed. I have not been able to make sense out of a similar post. Using version 6.0.11. See image. Any help would be wonderful.
Are the Power zones connected to each other?
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Certainly not.
Too short for message so: Certainly they are not connected.
Not sure what is meant. I have a GND plane and a VCC plane. All the VCC connections are connected to the VCC plane. If i unfill the VCC plane you then see the ratsnest connections between all of these pins. If i fill, these connections disappear except for this half a connection.
Try drawing a track from that pin 16 to another Vcc pad.
thanks for your suggestion, i did that and i still get the same error message. This ratsnest trace is also still there. I cant grab it to delete it.
May we have a more complete picture of the surround of u5?
Your VCC plane have to have two separated islands.
To one another he probably can. He should try to connect all VCC pins with track to find that he can’t.
I have a blown-up view having connected pin 16 to another VCC pin. As you can see the unconnected trace now is connected to this new trace. I also include an expanded view to show some of the surroundings. This shows that there is another 74ls173 which does not display this problem.
Thanks for your help
Here is your unconnected VCC plane island.
It is filled as it has connection to U9 VCC pin but it has no connection with rest of VCC plane and it is what KiCad tries to tell you.
It is not a problem related to any IC but a problem of lack of connection at PCB.
You are a genius. I connected the pin to a VCC pin on the island and the problem went away. Thanks a lot.
I’m not going to check this carefully, but I assume Piotr is right. In that case we have discussed this kind of problem before. See for example pcbnew: DRC - unconnected pads should not be shown as pairs (#7416) · Issues · KiCad / KiCad Source Code / kicad · GitLab. There was some discussion here, too. Basically the software can’t logically know what item the user understands as being connected or non-connected; therefore the ratsnest line and the message is only a suggestion for what to look at. The net is split into separated areas and you have to identify them and connect them.
Thanks a lot. I would never have thought of this and therefore found the right post.
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Good to read that the problem was easily found with a “big picture”. 
It was past my bed time. I’d gone.
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