If there is an error during startup, hit Tab to show the detailed error information.

Boot into recovery mode: Hold ESC and Reload (circle) keys when powering on, keep holding until something appears on the screen.
https://www.google.com/chromeos/recovery


Error during startup or recovery: "The security module on this device is not working"
This solution did work for me on an Acer:
https://support.google.com/chromebook/thread/11392753/chromebook-asus-c302c-0x2b-0x2b-secure-nvram-tpm-initialization-error?hl=en

At the restore screen, with the AC plugged in, press Refresh + Power (the screen will go black), WHILE holding those buttons in, unplug the AC. Let go of Refresh + Power. The screen might come back on at this point, but it will shut off automatically. If it worked, you won't be able to power the unit back on with the power button. Plug in the AC, and the unit should power back on.