Have a look at the headers; there is a pin next to the 3.3V pin.
The red button is also connected to the reset pin.
What is the serial-to-usb converter on your board; it's the chip closest to the USB connector. If it's not the CH340, you can run the loopback test and report here.
What happens when you press and release the reset button? You should get a few flashes in quick succession on the L-LED before the loaded sketch starts. If the loaded sketch is the factory installed blink, the L-LED will then change to the 1 second on / on second off; we're interested in what happens before that (the quick flashes).
I've moved your topic to a more suitable location on the forum.