After hours of reading and searching threads, I haven't found anything that helps.
This is what I have tried:
1. Use KF_SRT_v2.1 option2 to restore the 8.1.4 system.img
2. Flash boot.img and recovery.img
fastboot -i 0x1949 flash boot boot.img
fastboot -i 0x1949 flash recovery recovery.img
3. Erase userdata and cache
4. Reboot the kindle. It comes up fine and in Device > About is shows version 8.1.4
5. Copied update-kindle-8.4.6_4620220.bin to the root of the Internal Storage
6. The Update Your Kindle button remains greyed out.
I have also used KFFirstAide option7 to restore 8.1.4 system, boot, and recovery
and then erased cache and userdata. Again, the Kindle comes up running 8.1.4 but
the Update Your Kindle button remains greyed out
I have also tried the following:
a. KFFA option 22. UnRoot The Kindle - Do This Before Sending Back To Amazon
(This seems to work because the Root Analyzer app shows the Kindle is NOT rooted)
b. KFFA option 19. Enable Amazon OTA Updates
c. Factory reset
d. The Sync button on the Kindle
I am still sitting at 8.1.4 and the Kindle will not update via Sync, nor will the
Update Your Kindle button become active so I can update via the .bin file on the SD Card.
If I ran KFFA Option41. Kindle Fire 2nd-bootloader + TWRP 22.214.171.124 for KFHD 8.9 would I
then be able to flash the 8.4.6 .bin file using TWRP? I seem to remember being able to
use TWRP to reflash the stock Amazon O/S on my original Gen1 Kindle.
I have done this a couple of times with the KFHD7 and the Update Your Kindle button always
activates and runs the .bin file with no problem. Why is the 8.9 Kindle any different?
Any ideas would be appreciated.