[Fire HD 8 and HD 10 General] JJ2017:
OK - this time I really have borked it! Seriously, need help.....

Used MTKclient to flash partitions from the downgrade ROM - all fine at this point.

Still seem to be stuck in "Fire" loading loop - noticed additional "Flash tools" tab for reading & writing preloader etc. Foolishly flash preloader using Maverick_preloader.bin (from the Downgrade files).

Obviously, flashed the wrong thing as now tablet doesn't boot at all. MTKclient failes to connect to giving "Error uploading da" - see attached photo of output.

MTKbypass still works - bootrom is still accessible but when I run kamakiri get the folowing error about problem with corrupted Boot0:

[2022-03-27 17:21:28.476035] Waiting for stage 2 to come online...

[2022-03-27 17:21:28.601584] All good

[2022-03-27 17:21:28.603024] Flashing GPT

[34 / 34]

[2022-03-27 17:21:29.087906] Check GPT

[2022-03-27 17:21:29.264899] gpt_parsed = {'kb': (64, 2048), 'dkb': (2112, 2048), 'keys': (4160, 16384), 'misc': (20544, 2048), 'lk': (22592, 2048), 'tee1': (24640, 10240), 'tee2': (34880, 10240), 'metadata': (45120, 65536), 'boot_para': (110656, 2048), 'nvcfg': (112704, 16384), 'spmfw': (129088, 2048), 'sspm_1': (131136, 2048), 'cam_vpu1': (133184, 30720), 'cam_vpu2': (163904, 65536), 'cam_vpu3': (229440, 30720), 'boot': (260160, 65536), 'recovery': (325696, 83904), 'vendor': (409600, 589824), 'system': (999424, 6291456), 'cache': (7290880, 1032192), 'userdata': (8323072, 113819615), '': (0, 1)}

[2022-03-27 17:21:29.265019] Check boot0

Traceback (most recent call last):

File "/root/Desktop/kamakiri/modules/main.py", line 144, in <module>

main(dev)

File "/root/Desktop/kamakiri/modules/main.py", line 43, in main

switch_boot0(dev)

File "/root/Desktop/kamakiri/modules/functions.py", line 41, in switch_boot0

raise RuntimeError("what's wrong with your BOOT0?")

RuntimeError: what's wrong with your BOOT0?

Can anyone advise?

======================================================

Edit:

have managed to clear the error in Kamakiri by formatting preloader using Flash Tool - as described in https://xdaforums.com/t/new-fire-hd...k-brainstorming.3979343/page-42#post-86532337.

Close shave - note to self: don't recklessly flash things in MTKclient !

Still bootlooping Fire OS but a soft brick still has hope!

@789mod - thanks for your suggestions - I'm not sure that's where my problem is - have FireOS iso & MTKclient running OK off USB drives no problem. The downgrade just doesn't seem to work- but I keep trying .....

========================================================

Edit#2:

Nailed it! Fire OS 7.3.2.2 ----> 7.3.1.0 (y)

Followed the guides, as previously mentioned, and got stuck.

When stuck at 'Fire' OS loading screen, one thing that did seem to help was booting into to recovery: no options to select just stupid exclaimation mark in triangle.....

......However - randomly pressing power, +vol, and -vol buttons got me into recovery options - did factory reset - and from there Fire OS partially booted (e.g. language selection screen).

Re-flashed 7.3.1.0 partitions using MTKclient - hey presto 7.3.1.0 !

Thanks @AmznUser444 Dev for this post: https://xdaforums.com/t/hd10-9th-gen-2019-demo-model-reset.4409915/post-86630935 - which gave me the idea of getting into recovery past the "!"

Hope this helps someone else attempting this roll-back.