Tutorial: Turn back the clock – Downgrade your T-Mobile G1 to Android OS RC29

Update your T-Mobile G1 to Android OS RC30, did you? Unless you updated your G1 with a hacked version of of the Android OS RC30 firmware, you’re probably missing out on the root access right about now.

Wax nostalgic about root access no more!

A newly released Android RC29 firmware from xda-developers member chavonbravo allows Android users to downgrade their T-Mobile G1 back to the older firmware. The Android RC29 build retains the root access security hole that allows hackers to do all kinds of nifty stuff with their hacked G1.

Downgrading to RC29 is simple. Follow the below steps to downgrade your T-Mobile G1 back to Android OS RC29.

  1. Download the Android OS RC29 firmware file here.
  2. Rename the file to update.zip
  3. Copy the newly renamed “update.zip” file to root directory (base level, no folders) of your microSD card
  4. Disconnect your T-Mobile G1 from your computer if you used the data cable to access the microSD card
  5. Turn off the handset by holding down the “Power” button
  6. Turn it back on while holding down the “Power” (End Call) and “Home” buttons
  7. When you see “Triangle” icon, open the keyboard and press “Alt” and “L” simultaneously
  8. When you see some yellow text, press “Alt” and “S” simultaneously
  9. Follow the on-screen instructions
  10. Press “Home” and “Back” buttons simultaneously when you’re done and ready to reboot
  11. The G1 will reboot as it does its thing – let it do so.
  12. Enjoy Android RC29 and its root access security hole.

Now, you’ll probably be looking to update back to Android RC30 while retaining root access. Keep in mind that the root access update method is not as simple as the RC29 downgrade outlined above. But, with a little focus and patience, you’ll be just fine. Find our RC30 root access update tutorial here.

Android OS RC29
IntoMobile’s RC30 root access update guide

  • Well

    It fails to execute on my g1. “No signature found, aborting.” Any help? Thanks in advance.

  • Mike M. Allen

    Well, your screwed.

  • Vis0nz

    Its because this tutorial is missing a file needed in order for the process to complete.

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