Can I recover bricked device from Mask ROM mode?

[Conjada]

I suspect that your battery is too low to boot properly. Even hooked up to the charger and fully updated, the battery still seems to discharge, albeit slowly. Turned off and disconnected from the charger, it willstill discharge.

There are some power management issues on PPP, waiting to be worked out. If you have access to an external battery charger (such as recommended in @Otter post on anti brick devices), i would start by charging the battery back to full state and putting in a fresh sd card (i am using archlinux phosh with few difficulties so far).

Fwiw, i and others have noted that by inserting an sd card and simply booting by plugging in the charger, no button pushes are necessary to bypass the emmc. Strange, but true.

My shutdown procedure for now is disconnect from charger (or it will simply reboot after shutdown),
Shutdown from the menu,
Remove the battery and put it on the charger to restore it.

I suspect that people like @Danct12 or someone else will soon find what is causing the charging issue

UPDATE 20220131 : Fully updated Archlinux Phosh is now charging while using the Pinephone Pro. Im doing some studies now with the phone on, but unplugged from charger to find out how fast the phone is discharging and to try and see exactly whats drawing the most power while the phone is quiescent.