Rooted Nexus running stock 6.0.1 M4B30Z. Phone suddenly switched off and went into bootloop and haven't been able to re-flash stock... bootloader unlocked, fastboot working but no flashing possible (constant flash write error).
I managed to temporarily install TWRP using the excellent NRT v.2.1.9, but still unable to install anything. Seems the problem is storage cannot be mounted with the message 'unable to mount storage'. Again, managed to push the stock ZIP onto the sdcard but can't install.
Anyone got an idea of what it could be? is the device a certified brick now?