MacBook Air 2020 Won't Turn On – Need Assistance Diagnosing

Hello,

I have a MacBook Air 2020 that suddenly stopped working overnight. I’m not sure why it died, as it has never been exposed to liquid damage. I’ve already followed the troubleshooting guide found here: MacBook Will Not Turn On.

Here’s what I’ve tried so far:

• SMC reset, NVRAM/PRAM reset, and hard reset: None of these solved the problem.
• No signs of life: The keyboard backlight doesn’t turn on, the touchpad doesn’t click, and there are no boot sounds.
• Power source confirmed working: I’ve tested the power source, and it’s fine.
• Battery disconnected and boot attempt: I disconnected the battery and tried booting while plugged in—no success.
• Firmware reinstallation: I connected a working machine to the MacBook, and it detected the device but displayed a message like “USB device cannot be used.” It could however not restore the firmware, it never showed up.
• USB-C port testing: I used a tester, which showed a constant voltage of 5.11V and an amp reading of 0.3A. However, the amp would sometimes drop to 0.11A when I held the power button.
• Touchpad disconnected: I disconnected the touchpad and tried booting the machine without it, but it didn’t help.

One thing that gives me pause is that a light turns on whenever I plug the machine in, which makes me unsure if the logic board is the issue.

At this point, I suspect the logic board may be faulty.

One thing that gives me pause is that a light turns on whenever I plug the machine in, which makes me unsure if the logic board is the issue.
Are there additional steps I can take to confirm this diagnosis? Or is there anything I might have overlooked?