Upgrading Android G1 From Older CyanogenMod Versions to 4.2.3.1

This guide will tell you how to upgrade from an older version of CyanogenMod to the latest and greatest versions!

1. Download: Android 1.6 Recovery Image. Look for the 1.6 recovery image called “signed-dream_devphone_userdebug-ota-14721.zip.” FWIW, you won’t be able to download it from your phone because there is a weird popup license you need to agree to.
2. Download Cyanogen’s ROM (v4.2.3.1 – stable version, updated 10/31):
   Download: http://n0rp.chemlab.org/android/upda…3.1-signed.zip
   Mirror1: http://android.phaseburn.net/mirrors…3.1-signed.zip
3. Mount your phone and place BOTH the HTC 1.6 Image and Cyanogen’s ROM in the root directory of your SD Card.
4. Turn your phone off.
5. Hold the Home and Power buttons to get to Recovery Mode.
6. Perform a Nandroid backup if you’d like to (optional, but highly recommended).
7. When you are returned to the Recovery Mode menu, select the option “Apply any zip from SD”.
8. Select “signed-dream_devphone_userdebug-ota-14721.zip”, and then press the Home button to confirm.
9. Do not reboot your phone yet!
10. Once installation is complete, select the option “Apply any zip from SD” again.
11. This time, select “update-cm-4.3.2.1-signed.zip”, and then press the Home button to confirm.
12. When this is complete, reboot your phone.

Troubleshooting

• The upgrade should leave your already installed applications and data intact. You have to open the Market to rebuild your application database, or you will not get application updates.
• If you accidentally boot the 1.6 image it will install the HTC stock recovery. Booting back to recovery will show the /![] symbol. THIS IS NOT LOSING ROOT. You can still flash update.zip files from this recovery. Also, you can still flash a nicer (CM-1.4) recovery with fastboot, or flash_image inside the CM install once you get it installed.
• On G1, sometimes one can’t get through the T-Mobile boot logo (there was a write-failed error message about radio right before reboot). Try the following:
  • Wait long enough. Really long to ensure it’s not a regular (long) boot on upgrade.
  • If after 5-10 minutes you are sure (same logo), take out the battery
  • Wait around 10-15 seconds and put it back, holding Home + Back buttons to get into CM recovery
  • Select Restore Nandroid backup
  • Reboot
  • Repeat the upgrade steps on this page from the beginning. For some reason it worked all fine with 4.3.2.1 on second attempt.

I finally got around to upgrading to the latest mod (4.2.3.1), and it’s totally worth doing, even if you have to reinstall your apps once more — but you probably don’t have to. Cyanogen must have done some serious optimizing, because my G1 is noticeably faster now. It was a pretty simple upgrade once I found the right instructions (there are lots out there).