I've had an Atomic Pi with the Baby Breakout board for about 2 years, and have been using it without issue.

Unfortunately, the system won't boot up any more. Nothing ever shows up on screen, and nothing lights up when an Ethernet cable is plugged in. Plugging in a USB device with a light, it doesn't light up.
The power LED on the breakout board does light up however, and I notice that this chip on the back [circled: https://i.imgur.com/3UpGxQ0.jpg] heats up when power is on. I'm guessing this means that power is reaching the board, but don't know how to proceed from here.

I've tried unplugging the CMOS battery and pressing the adjacent switch to no avail.

When it was working, I recall hearing the coil whine change during the startup phase. I can still hear the coil whine, but beyond the initial blip when powered on, I don't hear it changing any more.

Does anyone have any idea on what can be done to diagnose/fix the issue? Note that I have basically no electrical skills.