The buzz probably means your regulator's pushing high current. If the chip heats up, it's more likely the chip than a capacitor. Or something's jacked up with the regulator and it's pushing high voltage, resulting in high heat, but it somehow bottomed out in your hub and turned off the buck hence why no Vcore measurement.
Thanks, sidehack.
I bet it's the regulator, as in the hub it doesn't heat up but sometimes flashes purple for a sec and posts a few HW errors, but directly in the tower USB 3.0 port, it begins to heat immediately. I may use this stick to eff around with and build skills. I've only ever frankenstein'd basses and guitars and a couple of A/D audio convertor boxes, so this will be a much smaller/finer challenge. My (3) compacs are at ~50 GH/s so I'm not cryin'. Chalk it up to experience. Maybe a 2PAC in the future once you catch up (or BMJ for double price, lol)
Thanks, sidehack. You're doing the lord's work (says the atheist, lol)! But seriously, rock on!