Iphone 3G 4.0.2 Lagging/freeze + poor battery

[Erhead]

Hi

I got a Iphone 3G 16 GB for free from a friend.
He was fed up with it, freezing, lagging, very poor battery etc.

He bought a Iphone 4.

It is a US bought phone, i live in Norway.
I have never owned a Iphone, but always wanted one.
Afer a weeks use, i am in love!!

So, this is what my question is: how to downgrade from 4.0.2 to 4.0.1, and what sofware do i need?

I have Cydia installed on my phone.

Honestly, i do not care if it is Jsilbroken, i just want it to work with my SIM, and not lagging.

Afer reading on the Cydia App, i learned that 4.0.2 is no good.
So hopefully my Iphone will work better with 4.0.1....?

Here are the details off my phone: Version-4.0.2 (8A400)
Model- MB048LL, modemFimware- 05.13.04

Yesterday i tried to downdgrade it in DFU mode, in Itunes.
Not working, i learned today that i have a 3G, not a 3GS, as i thought yesterday...(i`m a noob)

I obvioulsly had the wrong package.

All help is much appretiated!

Regards

[nlastella]

Well since it is a 3g, this should be remotely easy. First thing I would do is check if it has SHSH blobs saved for anything PRE-4.0. 4.0 is where mine started to bug out.

To find SHSH download "TinyUmbrella" and run it. Once running, plug your phone in and click save SHSH.

If you see 3.1.2 or 3.1.3, something along those lines, this should be pretty easy.

If you do, you want to have your iPhone plugged in and the firmware you are wishing to downgrade to already pre-downloaded. Next you should press the "Start TSS Server" button which will make this process a little more possible.

From there you can "Shift+Restore" your iPhone in iTunes to whatever firmware. After it's done it should say there was an error. That's ok.

So now that your phone is stuck in recovery mode, you go back to TinyUmbrella and click the "Exit Recovery" button.

Congratulations your phone is now downgraded to a firmware of your choice.

[Erhead]

Thank you nlastelle, i will give this try!

Sorry, i got your name wrong!

[Simon]

You dont need SHSH to downgrade to 3.1.3 on a iPhone 3G. Just put the phone in dfu, shift restore to a 3.1.3 firmware. When you get 1015 error exit recovery with tiny umbrella. Then you can use redsnow 0.9.4 (guide at top of page) or jailbreakme.com to jailbreak.

[Erhead]

Nlastella/x98car: Why do i need to downgrade to 3.1.3?
On cydia it says that jailbrake works until 4.0.1.

Anyway, i tried the steps from Nlastella yesterday.
When i pressed Save my SHSH, a list of firmware versions showed.
I cant remember exactly, but someting like this: 4.0 & 4.0.1 & 4.0.2 & 4.2.1
Nothing like 3.1.3, am i in trouble then?

I put the phone in DFU mode, i had the 4.0.1 for 3G pre-downloaded, and hit Shift + recover in itunes, but itunes did not se any .IPSW file.

I am soon to travel to Dubai, so i will not have time to try again in a couple of weeks.

But thank you both, for helping me out!

[iYeow]

When you run itunes, shift + restore will bring up a box for you to browse. If you download is in the form of .zip, then rename .zip to .ipsw

[Erhead]

When you run itunes, shift + restore will bring up a box for you to browse. If you download is in the form of .zip, then rename .zip to .ipsw

Yes, i did that. I have WinRAR installed, so the file showed with no file extension (like .IPSW).

So i pressed rename file, and added .IPSW at the end.

[iYeow]

Go to control panel > folder option > unhide extension.

You cannot just add the extension, it has to be renamed and do not extract.

[nlastella]

Nlastella/x98car: Why do i need to downgrade to 3.1.3?
On cydia it says that jailbrake works until 4.0.1.

You don't have to downgrade to 3.1.3 but I found that any firmware above 4.0 on the iPhone 3G ran terribly. By terrible I mean exactly what you said you're experiencing. I think 3.1.2-3.1.3 are the optimal firmwares for the phone.

[Simon]

+1 3.1.3 is the best firmware for a iPhone 3G