Because I know there's probably others in this situation:
I've been checking the power supply components to the OpenSDA USB port.
Here's the tests I've performed with a multimeter.
-My computer's USB rails read 5V.
-The voltage across the K20's VREGIN and GND pins is 5V.
-The voltage across the K20's VOUT33 and ground is 3.3V.
-The voltage across the K20's VDD1 and GND is 3.3V. VDD1 and VDD2 are tied together so both are 3.3V.
So far the analog power components are in working condition.
The K20's Reset_N signal is at logic high and it measures 3.44V
I need to leave for now. But this gives me hope that maybe the firmware is not responding rather than that hardware being damaged.
Again, thanks in advance to any kind folks with troubleshooting suggestions!