You can skip this section unless you have reason to believe your Pi Zero isn't alive.
The Pi Zero doesn't have much in the way of blinky LEDs to give you a warm fuzzy that it's doing anything or even alive. And if the GPU doesn't find a valid OS image, it doesn't even turn on the green ACT LED and looks totally dead. Typically this just means something is up with the SD card. Bad card. Bad image. Out of date image. Whatever. It does not mean the Pi Zero is dead.
- Take your Zero, with nothing in any slot or socket (yes, no SD-card is needed or wanted to do this test!).
- Take a normal micro-USB to USB-A DATA SYNC cable (not a charge-only cable! make sure its a true data sync cable!)
- Connect the USB cable to your PC, plugging the micro-USB into the Pi's USB, (not the PWR_IN).
- If the Zero is alive, your Windows PC will go ding for the presence of new hardware & you should see "BCM2708 Boot" in Device Manager.
- Or on linux, run sudo lsusb or run dmesg and look for a
ID 0a5c:2763 Broadcom Corpmessage. If you see that, so far so good, you know the Zero's not dead.
Below is a Pi Zero connected to a Linux computer via a USB cable and the resulting dmesg output. Note: there is no SD card installed, USB cable is in USB port, and there are no lights.
Here's what our Windows machine showed:
Looks dead, but it's not.