Howto: Unroot your Android G1 and get it back to stock factory firmware

When your phone wont boot into the android OS and cannot get to the recovery console, and all you see is the G1 startup screen you basically have one option to try and save your device with this method. Or you may want to get back to stock firmware because your rooted your device and want to send it back where you got it without voiding the warranty.

1. Save File: G1OrigBootloader_nocheck.zip to /sdcard/update.zip
   

2. Reboot with CALL + MENU + POWER, Hold in HOME + Power to enter recovery, then press ALT+S to Flash

3. Save File: DREAIMG.nbh to /sdcard/

4. Shutdown your G1 Completely, then Hold(camera+power) until you see a bootloader
   
5. Press power to start the update, sit back, relax, wait 30 mins, dont do anything but wait.
   
6. Did you wait long enough? If in doubt keep waiting...
7. Press Action(trackball key down) and your phone will reboot

You now have Stock firmware and should receive a OTA Update in a few minutes, if your returning your phone, you shouldnt really have to worrie, ive seen devices returned that had a new spl and rom installed, I think the insurance company just flashes them without really inspecting too much.