How To: UnRoot Your MyTouch 3G/MyTouch 1.2 MyTouch and Get Back to Cupcake (Updated 04.19.10)
UPDATE: THIS NOW WORKS ON THE MYTOUCH 1.2 (THE MYTOUCH WITH THE 3.5MM HEADPHONE JACK AT THE TOP) AND THE OLD MYTOUCH AS WELL.
1. Download the correct .nbh file for your device and rename it to sappimg.nbh if necessary (make sure it is sappimg.nbh and NOT sappimg.nbh.nbh or anything else)
NBH File (Works for the Old MyTouch)
Zip File (Works for the new MyTouch w/ 3.5mm headphone jack) RENAME IT TO sappimg.zip (not sappimg.zip.zip, just sappimg and its a .zip file!) Thanks Caesar for sending this in!
2. Save the sappimg.nbh/sappimg.zip file to your SD card. As always, do not place it in any folder on the SD card, just on the SD card.
3. Put the SD card into the phone and turn the phone on by holding down Volume Down and Power.
4. Push the trackball down on that screen and wait for it to pick up the Sappimg.nbh.
5. Push the trackball to begin, it should automatically update from there.
6. Once the flashing is fully complete, reboot the phone. DONE!
Issue: Phone says that the wrong Main Version is Older or Wrong Model ID…
Solution: Use our Goldcard Method instead.