iPhone 3GS No Service

Some iPhone 3GS owners face “No signal” or “Searching” error after downgrading their phones to 05.13.04 from 06.15.00. Before, following this guide we’re assuming that you’ve already used Redsn0w 0.9.14.b1 or later version to downgrade to 5.13.04, your device is now jailbroken and latest Ultrasn0w is installed. You can use Sn0wbreeze too for this purpose.

Here’s a simple guide to fix no signal issue.

1. Open Cydia and search for “Mobile Substrate”.


2. After finding Mobile Substrate, tap on it and hit the “Modify” button at the top right corner.

3. Now you’ll see three options: Re-install, Remove and Cancel. Choose “Re-install” option.

4. After performing previous step, don’t tap on “Confirm”. Instead opt for “Continue Queuing” as it can help you in doing more than one re-installation if required.

5. After re-installing mobile substrate restart your iPhone 3GS.

6.  Now head over to Cydia > Manage > Packages and search for “Ultrasn0w”.


7.  When you see it, tap on Modify > Reinstall > Confirm and wait for the re-installation process to complete.

Once you do all the above steps, “No signal” problem should be fixed. This problem usually occurs when some files get corrupted during 06.15.00 baseband install or baseband downgrade process. If this method works for you or if you tried some other trick to fix this issue then feel free to tell us in comments.