HTC Desire Z Firmware Downgrade (Gingerbread)

This guide will walk you through the process of taking the HTC Desire Z from stock Gingerbread firmware to a stock, exploitable version of the Froyo firmware. Once it is downgraded, you would proceed thru the process of getting CyanogenMod on the device. If the HTC Desire Z is already running firmware version 1.34.xxx.x or lower (Settings » About Phone) you can skip to the vision install guide guide.

Downgrading to 1.34.707.3

1. You will need ADB on the computer to proceed thru this process. Follow the Android SDK guide to get the ADB shell on the computer.
2. Download fre3vo, misc_version 0.2 & the 1.34.707.3 firmware:
   • fre3vo: Download

     md5: 010e076a4a93be876579711bf8934c70

   • misc_version 0.2: Download

     md5: 1f40aaf88d1bf15775631a58c4361218

   • flashgc: Download

     md5: 86e6e81fad3b3c837ed8bd09b6005651

   • 1.34.707.3 firmware: Download

     md5: 8aa11b9e9db9877b029f37caec49547d

3. Unzip the fre3vo & misc_version packages and save flashgc to the same folder as adb (the /platform-tools folder within the Android SDK folder).
4. Make sure the filename of the firmware is PC10IMG.zip exactly or it will not work and copy it to the same folder as adb.
5. Connect the HTC Desire Z to the computer via USB.
6. On the computer, open terminal and run the following commands:

   adb push fre3vo /data/local/tmp

   adb push misc_version /data/local/tmp

   adb push flashgc /data/local/tmp

   adb shell

   chmod 777 /data/local/tmp/fre3vo

   chmod 777 /data/local/tmp/misc_version

   chmod 777 /data/local/tmp/flashgc

   /data/local/tmp/fre3vo -debug -start FAA90000 -end FFFFFFFF

   adb shell

7. You should have the “#” sign instead of the “$”. If you do, you have temporary root, and can continue on. If you have the “$”, then the exploit has failed, refer to xda developers, RootzWiki, or #G2Root for further assistance.

   cd /data/local/tmp

   ./misc_version -s 1.00.000.0

   ./flashgc

   exit

8. Now that misc version has been downgraded, the HTC Desire Z is ready to have the firmware downgraded. On the computer, open terminal and run the following commands:

   adb reboot bootloader

9. Wait for device to reboot into bootloader mode

   fastboot oem rebootRUU

10. Wait for a black screen with the HTC logo

    fastboot flash zip PC10IMG.zip

11. If you see a message saying Failed, repeat this step immediately: fastboot flash zip PC10IMG.zip and it should succeed.
12. Once finished you can can continue to the next section.

Note

You need to insert an SD card in your phone and use “charge only” mode on the phone.

Rooting the HTC Desire Z

Please follow the vision install guide to continue.