[How-To] Downgrade your Touch Panel's firmware (and upgrade back)
Quick Note to the Mods: I placed this in Android Original Development forum as this is now a requirement for all AOSP Roms here after a user takes the Jellybean OTA, otherwise they can only use Sense ROMs. I'm aware this is a How-To, but I hope you agree with its placement.
WARNING: This messes around in rebootRUU mode which is dangerous. Follow instructions PRECISELY and you shouldn't have any issues. This is only necessary for users that took the Jellybean OTA that are on the 2.14 hboot
Allow users that took the Jellybean OTA and upgraded their touchscreen firmware (Thanks HTC). Now their touchscreen does not respond on any AOSP ROMs (as of this time).
* ADB/Fastboot installed
* Bootloader Unlocked
Downgrade your Touch Panel's firmware:
1) Download downgrade_tp.zip
to the location where you store adb and fastboot
2) Open a terminal or command line
3) Change directories to the location where you store adb and fastboot
4) Plug your phone into your computer via USB. Issue the following command.
adb reboot bootloader
5) Once bootloader appears, wait for Fastboot USB to be shown on the screen. Then issue the following command.
fastboot oem rebootRUU
6) A black screen with HTC logo on it should appear. Issue the following command.
fastboot flash zip downgrade_tp.zip
7) You should see the following output.
NOTE: DO NOT continue further until you see the "finished." line.
sending 'zip' (44 KB)...
OKAY [ 0.209s]
(bootloader) zip header checking...
(bootloader) zip info parsing...
(bootloader) checking model ID...
(bootloader) checking custom ID...
(bootloader) start image[tp] unzipping & flushing...
OKAY [ 28.881s]
finished. total time: 29.090s
8) You will notice that the HTC logo and load bar are still present and fastboot doesn't see any devices. See here for a screenshot
9) Reboot the device by powering it down with your power button (it will restart after its turned off).
10) Enjoy the downgraded firmware and go flash some AOSP ROMs like CM/AOKP, etc.
If you wish to revert back to the newer firmware
Follow steps #1 - #10, except use this upgrade_tp.zip
instead of downgrade_tp.zip. This will return you to the newer touchscreen firmware that came with the Jellybean OTA. I'm not sure if this is necessary, but I am unsure if Jellybean-based Sense ROMs require the newer touchscreen firmware.
02/21/13 17:40 CST - Cleared up an issue where downgrade_tp.zip forced you to go to recovery and clear cache to boot into a ROM.