IT'S WORKING!
After some rest, I tried again this morning and noticed that if I held the USB cable juuuuuuuust right I would get a connection.
I looked under the microscope and it looks like three of the USB connector pins are not completely soldered, so I touched them up and it's all fine now. They are sort of soldered underneath the pin, but it's not real great. My other UB4 connector soldering looks even worse, so I'll touch that up also. MAN, the pins on that connector do NOT want to take solder even with flux. #supplychain
Anyway, I'm back up and running and won't power with two supplies at the same time again just for safety.
Thanks Dave,
Alan KC1QHV
