I have cut the VCC jumper on my 32u4 breakout board. I then tested for continuity across these pads with my cheap analog continuity meter and there is still a significant buzz sound (though not nearly as loud as the when I touch the probes to each other. I then went to measure the resistance across the jumper and the resistance was too high to register on my meter.
I then plugged it into my computer and see that it is no longer enumerating, as expected as the chip should not be getting power. However, I measured a few pins on the ISP header and elsewhere and noticed several pins were floating around 1-1.5V. Is this normal? Should I be concered by this when I hook up up my external 3.3V source?