Can I recover bricked device from Mask ROM mode?
I encountered the same issue with a corrupted eMMC install. I wrote a guide here: https://forum.pine64.org/showthread.php?tid=15921 but to summarize:
1. Remove USB-C power and the battery.
2. Hold down the power button for 10 seconds, release for 3 seconds, hold down the power for 10 seconds, release the power button.
3. Re-insert the battery.
4. Hold reset (pinhole top left named Re) while inserting USB-C power.
5. Release reset after 4 seconds.
Please let me know if it works for you.
1. Remove USB-C power and the battery.
2. Hold down the power button for 10 seconds, release for 3 seconds, hold down the power for 10 seconds, release the power button.
3. Re-insert the battery.
4. Hold reset (pinhole top left named Re) while inserting USB-C power.
5. Release reset after 4 seconds.
Please let me know if it works for you.