Downgrade to 6.0.1 with TWRP backup?

[m4f1050]

Will downgrading to 6.0.1 with a TWRP backup of phone brick the phone? (I ask because downgrading bootloader has been proven to brick phone)

Thanks!

 

[echo92]

If you downgrade to 6.0.1 with a TWRP backup, it may not brick your device, since the TWRP backup should only restore the system, kernel and not affect your bootloader.

However, because your bootloader is not downgraded to 6.0.1 too (and you generally cannot downgrade bootloaders), you have a mismatched firmware - you have a newer bootloader but older system. It appears that taking OTA updates for older system firmware, when you have a newer bootloader than your system, can brick your device - the old OTA update appears to overwrite your newer bootloader and lead to a brick. OTA updates appear to only check if your system is the right build and assume the bootloader is the correct build, which if you've downgraded is not the case.

So if you do downgrade, please do not use OTA updates. If you must update, only use stock firmware to update your device. It is not the downgrading that bricks a device, it's downgrading and then using OTA updates in most cases that bricks devices. The only cases I've seen where downgrading and then using OTA updates has not bricked devices is when the user has rolled back to the firmware directly preceding their current latest firmware.