I implemented the solution for the 8 LED’s controlled by the 74hc595 chip. What happened was the LED’s came on and stayed on for about 500ms. Then all the LED’s turned off and have never come back on again. I tested the resistors and they are still reading 220 ohms as expected.
Has anyone come across this behavior before? Any idea what could be going on?
I did power cycle the UNO and tried re-uploading the firmware without any changes. The LED’s never came back. Powering the resistor manually does turn the LED on again as expected.