Vin and Ground pins shorting only under specific conditions So I have an Arduino Nano that I think might have gone bad. The Vin and ground pins are shorting (I'm checking continuity with a multimeter). But it only shorts when:


The Arduino has power
The red lead of the multimeter is on ground and the black is on Vin (not the other way around)


I've tried checking with the leads both ways (red to ground as well as red to vin) while both on and off, and with two different multimeters, one of which is brand new. Completely at a loss for words because this isn't really how physics is supposed to work (continuity shouldn't depend on lead orientation from the multimeter or whether the circuit is powered, right?). Any insight would be appreciated. Do I have a bad board?
But it only shorts when: The Arduino has power


You must not use a continuity checker or ohm meter on a powered circuit.

Not only will it not work, you risk damaging the meter.

It's also not necessarily safe to use such a meter on an unpowered active electronic circuit like an IC or eval board, as the meter must apply a small amount of power to the circuit to make a measurement - how much power varies between meters and settings, and how much a circuit can tolerate in an unintended way depends on things like polarity and the state of other parts of the circuit.  However, it is common practice to do so - especially for example when there's a fear that the device might already be damaged.