downgrade from 3.1.2 due to GPS issues, please advice

**eyal9911** · 12-24-2009 11:25 AM

I have permanent GPS locking issues, I’ve tried all known solutions, pushfix, reset network, timeout=never, wifi on/off etc. even recovery. It seems that after rebooting 1/10 times it locks and then works fine until I close the application. I am now thinking to downgrade the firmware and wanted to know what is the most known stable OSx.x+blakra1n that has no GPS issues? my phone was activated with AT&T sim, then unlocked and jailbreaked.

Many thanks!

**Olethros** · 12-24-2009 03:10 PM

Can you still activate with AT&T sim?

You can try downgrading to OS 3.0 and activating with AT&T sim.

Cydia must say that you have a 3.0 or 3.0.1 shsh on file. Then you must point iTunes at cydia or use tinytss/firmware umbrella to allow you to downgrade.

Then jailbreak with redsn0w

**eyal9911** · 12-26-2009 06:54 AM

Thanks. How to proceed with the downgrade? Cydia doesn't say "3.0 or 3.0.1 shsh on file"? How can I activate it in Cydia?

**Olethros** · 12-26-2009 09:59 AM

Originally Posted by eyal9911

Thanks. How to proceed with the downgrade? Cydia doesn't say "3.0 or 3.0.1 shsh on file"? How can I activate it in Cydia?

If cydia only says 3.1 and 3.1.2 shsh on file then you no longer have the option to downgrade to 3.0.x

Apple blocked downgrades to OS 3.0.x just 3 days after Cydia started offering this option. So you had to be quick and lucky to get 3.0.x on file.

**eyal9911** · 12-26-2009 11:51 AM

Apple is nice... Where do I find it in cydia? The main screen shows nothing. Do I have to run a special apps? I bought the iPhone used so I don't know the history. If 3.0 is not possible is it easier with 3.1? Can I downgrade with other software without having that signature history? Thanks.

**Olethros** · 12-26-2009 12:34 PM

Originally Posted by eyal9911

Apple is nice... Where do I find it in cydia? The main screen shows nothing. Do I have to run a special apps? I bought the iPhone used so I don't know the history. If 3.0 is not possible is it easier with 3.1? Can I downgrade with other software without having that signature history? Thanks.

Is it a 3G iPhone or a 3GS iPhone?

You only need to worry about the ECID / SHSH on 3GS iPhones.

**eyal9911** · 12-26-2009 12:47 PM

It is 3G. How to I perform the the downgrade in that case? Many thanks.

**Olethros** · 12-26-2009 02:02 PM

Originally Posted by eyal9911

It is 3G. How to I perform the the downgrade in that case? Many thanks.

Downgrade iPhone 3GS 3.1 to 3.0 (iPhone OS 3.1 to 3.0 Firmware)

If you are very lucky, you can also try the following (this can downgrade just the baseband). It only works for 3G iPhones made and sold just after the 3G iPhone was first released.

Downgrade iPhone 3G Firmware 3.1 Baseband 05.11.07 to 04.26.08 | Redmond Pie

**eyal9911** · 12-26-2009 02:57 PM

I'm not so lucky, my bootloader is 5.09 so the Fuzzyband can't downgrade the baseline (currently 5.11.07). Do I still have a chance to downgrade my 3G, unlock and jailbreak it? it currently runs 3.1.2 and have GPS locking problems?? Thanks.

**Olethros** · 12-26-2009 08:51 PM

Originally Posted by eyal9911

I'm not so lucky, my bootloader is 5.09 so the Fuzzyband can't downgrade the baseline (currently 5.11.07). Do I still have a chance to downgrade my 3G, unlock and jailbreak it? it currently runs 3.1.2 and have GPS locking problems?? Thanks.

Yes you can still downgrade the OS, but not the baseband. This link I gave earlier shows how to do this.
Downgrade iPhone 3GS 3.1 to 3.0 (iPhone OS 3.1 to 3.0 Firmware)

This may fix your GPS problem, depending on where the problem actually is.