For the last week I've had trouble powering up my new Pi. Initially I tried booting Raspbian while powering the board using a USB cable, but the activity light would not flash at all. I then tried with another USB cable, same issue.
At that point I put NOOBS on my SD card because I figured something went wrong when I tried to dump Raspbian onto it. However, the problem persisted. I took some measurements and found that I was only getting at most 8 mV running through the two USB cables.
After that, I connected my Pi to a powered breadboard I own via the header pins and set its voltage output to 5V. I verified with my multimeter that 5V was running to my Pi through the 5V+ and GND pins. Still no activity took place.
I tried a few more times to load different images on the card just to verify it wasn't a software issue, but nothing helped. I'm using an SD card that should be compatible with the Pi, a SanDisk Ultra SDHC 32GB.
While I understand each Pi is tested before it leaves the manufacturing facility, I'm led to believe I may have a dead or damaged Pi Zero. In spite of all this however, it does register as a USB device whenever I connect it to my computer, which is holding me back from being absolutely sure it's a dud.
Is there anything I'm missing that could explain why my Pi isn't working? Any help/suggestions would be appreciated.