Edit 2013-04-11 by PierreP: Try first the
Whited00r tutorial - Downgrade iPad Baseband on iPhone 3G to Unlock which includes a custom firmware to
automatically upgrade to unlockable baseband 06.15.00 and if you still have problems then try this tutorial:
[Solved] iPhone 3G iOS 4.2.1 Free Unlock Baseband 05.15.04 05.14.02 - No Service*****If your iPhone 3G is
Factory Unlocked, you do not have to upgrade/downgrade your Baseband 05.15.04 because the point of this process is to be able to carrier unlock it to be able to use SIM's from any cellular provider. Just follow the instructions here:
Whited00r Installation Tutorial and install Whited00r
Normal Version.
All other users, follow the tutorial below to free unlock your iPhone 3G on Modem Firmware 05.15.04
(a.k.a. Baseband or BB).
**********************Guys, lot of us have issue with NO SERVICE after Whited00r 6 upgrade because we have the dreaded Baseband 05.15.04 on our iPhone 3G. After week I came with solution, at least it helps me
If you followed this video tutorial carefully
http://youtu.be/Dlni70lFIy8 and your iPhone 3G is/was carrier locked (doesn't matter if its unlocked before upgrade) it's 80% chance you will get NO SERVICE ERROR and your baseband is 05.15.04, or something higher than 05.14...
SOLUTION A):
Install whited00r 6 UNLOCKED , if you have NO SERVICE, go to AppStore/Cydia/ultrasn0w > remove ultrasn0w > respring Cydia > install ultrasn0w > turn off iPhone > insert sim card and turn on device. Service should be found within 200 seconds. WORKS!
Doesn't work?
SOLUTION B)
1. Restore it in iTunes with iOS
4.2.1. official firmware2. Unlock it with
Redsn0w 0.9.6b6 [please note newer versions of Redsn0w 0.9.6... may crash ]. We Will be updating to 6.15.00 & Unlock Using Ultrasn0w
http://youtu.be/eBum96agsWY3. Downgrade 6.15.00 Baseband to 5.13.04 with
Redsn0w 0.9.14b2 http://youtu.be/srrXFHRZH9U - you should have service now!!!
4. Install
whited00r 6 UNLOCKED custom firmware in iTunes (restore with SHIFT key) -
whited00r 6 preserves your baseband, so you will stay on 5.13.04.
DO NOT RESTORE with OFFICIAL FIRMWARE AFTER DOWNGRADING as it's advised in
http://youtu.be/Dlni70lFIy85. ENJOY & post your feedback here to help the whited00r community!!!
Moderator note: Edited thread title to add relevant keywords as described in WD 6: Tips to Quickly Solve your Problems/Bugs & Get Answers FAST!, typos and also the broken video links. Added iREB screen capture with tips.