Help with dead A0 pin

Using Arduino Project Guidance
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FWIW, this is the typical input structure. As you can see, when the pin is pulled up, but VDD = 0, there's potential for current to flow. How much, depends on your external pullup. Whether that's causing your issue, I can't say, but I'd have my suspicions.

Best of luck, let us know what you determine.

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i will certainly address this regardless, but, and its a big but. The damaged pins seem to be A0 in both cases, yet the pin with voltage on it is D12. Perhaps they are in somewhat multiplexed inside the chip ?
Either way, this is the most likely candidate for now

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Have we seen a complete schematic for your circuit? Perhaps there are other possibilities.

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That sounds like your external,pull-ups are trying to overcome some other ‘external’ load as a design flaw.

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that is a possibility, one which i considered when adding the external pullups, I am going to go over the original schematic, and the actual connections and make sure they tally up ok, then I will post a schematic here to see if anyone can spot something I may have missed. (or am ignorant about)

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