[RESOLVED] Bricked after flashing firmware for Pie, stuck in md5 checksum bootloop

[BillGoss]

If you follow the process I suggested you will lose the data on the phone. I would not boot up on such an old OOS version because, I believe, the encryption had changed since then. So, format data using TWRP 3.3.1-0, copy across the latest OOS zip you want to use, flash it, and reboot. That way you'll have the phone encrypted properly for that latest version.
Then flash TWRP again in fastboot, boot into TWRP and flash or restore your other stuff.


Sent from my OnePlus 3T using XDA Labs

---------- Post added at 11:58 PM ---------- Previous post was at 11:52 PM ----------

Pardon me, but which file system would be most suitable for each partition?
The Wipe>Advanced Wipe menu offers several file systems for several partitions. I'm inclined to leave everything as it is, but should I perhaps format the /system partition as f2fs for instance?

Absolutely not! Leave them as they are.

The only one you should decide on is the data partition. After the format data step, which leaves it as ext4, if you want you can change the data partition back to f2fs (which is how the phone was shipped).
I personally didn't bother going back to f2fs after I ran the format data and I've not had any issues.

Sent from my OnePlus 3T using XDA Labs

 

[swumo]

If you follow the process I suggested you will lose the data on the phone. I would not boot up on such an old OOS version because, I believe, the encryption had changed since then. So, format data using TWRP 3.3.1-0, copy across the latest OOS zip you want to use, flash it, and reboot. That way you'll have the phone encrypted properly for that latest version.
Then flash TWRP again in fastboot, boot into TWRP and flash or restore your other stuff.


Sent from my OnePlus 3T using XDA Labs

---------- Post added at 11:58 PM ---------- Previous post was at 11:52 PM ----------


Absolutely not! Leave them as they are.

The only one you should decide on is the data partition. After the format data step, which leaves it as ext4, if you want you can change the data partition back to f2fs (which is how the phone was shipped).
I personally didn't bother going back to f2fs after I ran the format data and I've not had any issues.

Sent from my OnePlus 3T using XDA Labs

Thank you for your help, sir. I have indeed been prompted by the Restore tab to re-format /data to f2fs, which I've gone forward with.
I recognize your profile picture from several of the posts that I've lurked on in the forums for a couple of years, and I'm grateful that you take time to help others in need.

And thanks everyone for your help. The phone is back to 100% apps and their data, and I can probably get copies of lost material like photos or lectures from classmates.