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Gabriel Mergh , 08-11-2025, 12:55 PM

Hello Guys!

I hope everything is okay!

I'm developing a PCB in Altium (version 20.2.4), and during the design process, I used the rule checking tools and didn't find any violations indicating a short circuit.

However, when I received the finished board, I detected a short between VCC (V_BAT) and GND. Interestingly, in the design, all the nets were correctly assigned, including the polygons I created in the four stackup layers, which were defined with the GND net. I didn't find any incorrect connections or in the elements.

Even after carefully reviewing the design in Altium and using the Design Rule Checker, I didn't find anything suspicious. This leaves me wondering if I made a mistake using polygons or if I overlooked a clearance setting.

I've been watching videos on YouTube @Robert Feranec and am considering taking a course to deepen my knowledge, but I would really appreciate your help in understanding what might have caused this short.

If you could guide me on any points I should review more closely or if you have any suggestions on what to look out for in these cases, it would be greatly appreciated.

Thank you in advance for your attention, and any help will be greatly appreciated!

Gabriel Mergh , 08-11-2025, 01:07 PM

I also suspect I made a polygon for cutout. These were magnetic field sensors, and reading their datasheets indicated that current could not be passed underneath them for better performance.

Neur0nZ3r0 , 08-12-2025, 12:48 AM

No idea how I'd be able to find your GND short like this buddy

Neur0nZ3r0 , 08-12-2025, 12:48 AM

Post schematics etc

Robert Feranec , 08-12-2025, 05:27 AM

If you can't find it in layout, it could be in PCB. I would take the bare pcb and keep cutting the VBAT until I would find the position where is the short circuit. In some of the comments I have seen someone showing a short circuit on a plane layer and Altium was saying everything was ok. Also, I have seen PCB manufactured with short circuit.

QDrives , 08-12-2025, 11:31 AM

You are using an older verion of Altium. If I recall correctly, if you had shelved polygons, they would not repour. You DRC also does not check them. However, when you export to Gerber, they are exported, which may cause the problem.
Secondly, like @Robert Feranec mentions, it may be a production fault. is it on one board or multiple? What is the resistance?
One way you may be able to get rid of it is by 'burning' it out. If it is a hairline, then just applying a low voltage high current to them the thin copper sliver will burn up.
Are your clearances big enough? Perhaps a via is off slightly causing the short. Or a layer mis-registration.
Highlight the net in question and check everywhere it is close to Gnd (in 3D as well!).