WARNING: YOU WILL LOSE ROOT/S-OFF THROUGH THIS PROCESS THAT IS THE POINT.
The old sticky brings you back to the MR1/old release. My guide will be VERY simple and does not require reflashing hboot to get S-ON back, (if you used revolutionary method there may have to be an extra step which i will detail below)
Firstly download this guy to your sd card
For those of you who are lazy and dont want to read the android police thread here is a direct link to the file (or should i say the host to the file)
After you download the file, rename it to PG05IMG.zip and throw it on your sd card, reboot into hboot (not rommanager) get to the bootloader and let hboot do its thing (inspect your sd card for PG05IMG.zip)
Press volume up to accept all of the updates....
You should see your hboot return to S-ON...
FOR REVOLUTIONARY USERS ONLY all credit to this guide goes to scotty85 at android forums
how to unroot
the revolutionary method of rooting uses a sneeky hboot exploit,and replaces your stock 1.04.0000 or 1.05.0000 bootloader with a modified permanent hboot. it not only gives you all the same fashboot flash abilities as the original engineering bootloader,but it very effectively blocks other hboots for overwriting it. its good,as you will remain s-off if you accidentally flash a full RUU,or accept an OTA,but makes it a little trickier to remove.
for the time being, removal requires ADB to be set up and running and some commands entered in "fastboot" to to allow the permanent hboot to be overwritten. once an "s-on" tool is release,ill take th is part of this guide down.
if you rooted the old skool manual way and have adb setup and working,you can use this guide to remove the permanent hboot.
with Revolutionary,will come a new wave of rooters that have no clue what adb,or fastboot even are. for you folks, Sele and the crew in the "rescue sguad" at HTC Thunderbolt Forum have come up with a really clever way to get the adb basics,and the eng bootloader to flash,with minimal setup and confusion. with their permission,im borrowing it for our guide here.
*WARNING* no siginture or file checks will be done flashing the new bootloader in hboot or fastboot.fastboot will literally flash "lets golf" as a bootloader if you tell it to. DO NOT mess with your hboot unless absolutely neccessary to return to stock for warranty purposes. if youre just tired of being rooted,flash the gingerbread ruu to get back to unrooted firmware and factory recovery. leaving the revolutionary s-off bootloader in place is the safest,and best option,and will not affect your ability to recieve OTAs.
*AGAIN- if youre just following this procedure because youre tired of being rooted,skip this next section and leave the permanent hboot in place. jump to "Putting current stock firmware and s-on back onto the phone" and flash only the first "PG05IMG_2.11.605.5_no_hboot.zip" file(you can flash the 2nd file too if you want,but the permanent hboot will block it )
Setting up adb and removing the permanent hboot if youve never used adb before
1)if you no longer have the htc drivers that you installed when rooting with revolutionary,download them again from here on revolutionarys website.
2)next download this file to somewhere convenient that youll be able to find it,like your desktop,or a "downloads" folder. it contains the old eng 1.40.2000 s-off hboot,and the bare minumum tools to install it.
3)the following directions were using windows 7 and chrome browser. other OS may be slightly different-the end result is you want unzipped,inside tbolt folder to be on the root of your C: drive.
-find the tbolt.zipdownload
-click on tbolt.zip download and open it.
-inside tbolt.zip,there is a folder labled tbolt. drag it to the root of C:. inside tbolt is the unpermanent hboot and some adb tools.
4) charge your Thunderbolt to 100%
5)click on then "start" bubble in the lower left corner of your screen. type "command" in the search window and hit enter. this will open a small black command window.
6)enter the following command(by typing or copy/paste):
you should see your promt in the window change to: c:\tbolt>
7)enter the follwing command:
check the output on the command window. THIS IS VERY IMPORTANT. the command must equal exactly 6991368ee2deaf182048a3ed9d3c0fcb if it does not,STOP!. delete the tbolt.zip download,and the unzipped tbolt folder from C:,re download and try it again. again,do not procede if the output in your command number does not equal it exactly.
8)once the number matches,you can continue. copy and paste the following codes into the command window:
the output should be your phones serial number
adb reboot bootloader
this will cause your phone to boot into FASTBOOT mode,wich is a white screen with colored letters.
the result again,should be your phones serial number.
9) now youre ready to enter the command to unlock the permanent hboot and flash the new,non permanent one.
fastboot oem mw 8d08ac54 1 31302E30
write the new hboot:
fastboot flash hboot hbooteng.nb0
if you select bootloader at this point from the fastboot menu, youll still see the permanent s-off hboot,so select reboot with the volume rocker and power button and let the phone reboot. after it boots,you can adb reboot bootloader again,or power off, then power on/vol down and check that your pink "UNLOCKED" or "REVOLUTIONARY" is gone and you have the old 1.49.2000 bootloader.
here is what you should see in the command window,the red are my inputs:
Microsoft Windows [Version 6.1.7601]
Copyright © 2009 Microsoft Corporation. All rights reserved.
MD5sums 1.2 freeware for Win9x/ME/NT/2000/XP+
Copyright © 2001-2005 Jem Berkes - http://www.pc-tools.net/
Type md5sums -h for help
[Path] / filename MD5 sum
* daemon not running. starting it now *
* daemon started successfully *
List of devices attached
c:\tbolt>adb reboot bootloader
c:\tbolt>fastboot oem mw 8d08ac54 1 31302E30
OKAY [ 0.006s]
finished. total time: 0.006s
c:\tbolt>fastboot flash hboot hbooteng.nb0
Edited by nocoast, 09 December 2011 - 12:44 PM.