Why to downgrade 4.3.5 to 4.1 iPhone 3GS?

Do i need Shsh?

Can not open costume ipsw?!!?!?!?

How do you combine these 2 parts of ipsw. I am not able to figure this thing out.

Can this also be done on Iphone 4? And waht about the SHSH?

If this is true, someone just made my day!

But just like it's been said above, how on earth do I combine or even extract the 2 ipsw files?

I sincerely hope someone who knows, will find the time to answer and maybe explain.

Thanks in advance.

where is the shsh?

no idea how to combine.....what now?

I don't know if this is the correct answer to combine the files, but I was able to create a single file using the DOS Copy command on Windows that at least _seems_ to be valid.

copy /B file.ipsw.001+file.ipsw.002 file.ipsw

havin problems with this aswell how do I combine? and when i try to shift click to try one out it says the file is not compatible

http://www.hjsplit.org/windows/

to join the files

works great! thx u make my day!

Just did above on two 3Gs iOS4.3.5 BB5.16.02 ,old boots and no SHSH Blobs. Win 7 system would not validate ISPW. No errors on XP system. Used redsn0w win 0.96b5 not 0.96b6. Phones are now iOS 4.1 with BB 6.15.00 jailbroken and unlocked on T-Mobile and GPS is OK. Thanks more than I can say to all who posted these directions!!!

Used Mastersplitter free from cnet.com downloads to combine split IPSW file.

u use hjsplit to join the files!

No need shsh file, Apple still sign the 4.1 firmware. I use jdownloader for download and it extract the files to one file automatic. But there is a many other tool for that. Use google ;)

use Hjsplit to combine ;)

use winrar to extract these files.

I bought a iPhone 4 version 4.0.2
I upgraded to version 4.1 and 1.59 baseband with limera1n and Greenpois0n.
Today I updated to firmware 4.3.3 with Sn0wbreeze 2.7.3 and TinyUmbrella.
I have not had a single error record with itunes 10.4. The baseband has been well respected.
But GSM does not work now. The screen displays a message "no service" in the area where the bar should appear coverage. The operator's name also appears.
Does anyone know why that is?
Should I downgrade the version 4.1?
Thanks

Thank you Limera1n. It works! Just downgrade my iphone 3gs from 4.3.5 to 4.1 custom firmware ipsw. No need to jailbreak. The custom firmware is already jailbreked.It cams with cydia build in.To join the 2 ipsw files I used this program: http://www.hjsplit.org/
it is free.

Holy shit... it works...

Just downloaded this and it worked!, joined the two 001 and 002 files with HjSplit, took a little bit of tinkering tho. But yeah, I have successfully downgraded from 4.3.5 to 4.1 using this guide. Thanks!

just download sn0wbreeze 2.1 create a custom ipsw using the normal 4.1 then dfu resore

Hello Guys

You can join the files using HJSplit

to combine use http://hjsplit.org/windows/

combine the two files using hjsplit

download "hjsplit" program to combine. You don´t need SHSH since apple is still using for 4.1

Can anyone confirm that by performing the downgrade above, your baseband will change to version 06.15.00? Be advised if this is so, your GPS will no longer work.

Yeh just did this. had an english 02 iphone 3gs that would not work in ireland on 4.3.25 baseband 5.16.02
the only probs i had was i didnt run redsnow as admistrator and point it at stock ipsw. when i did that all work
thank you

Combine the files works.
Downgrade fails.
Use TinyUmbrella's TTS server works, restore looks works, however, iphone 3gs keep enter DFU mode, and can NOT start on...

I used this tutorial to downgrade my 3GS from 4.3.5 / 05.16.02 to 4.1/06.15.00. It is now jailbroken (untethered), unlocked, and working on the T-Mobile network with a perfectly functioning GPS. Thank you to the blog reader that provided the instructions. I have been waiting patiently for months for a solution and my patience has finally paid off.

I have 3gs 32gb. Also downgrade from 4.3.5 to 4.1 and it is true - it's already jailbreaked and Cydia is there. Thanks for best guide

Thanks for posting this guide. It works.I just downgrded my 4.3.5 to 4.1 and jailbreak my 3gs with 4.2 custom firmware and then unlocked it.
Thios the best guide on the web

I have 3gs 16gb IOS 4.3.5 and it do not have shsh. I want to downgrade from 4.3.5 to 4.1 (or 4.3.3,...).
This solution need shsh or not.
Thanks

if you still have problems, try adding the line to the end of your hosts (c:/windows/system32/drivers/etc/hosts) file before RESTORING, and also disable any antivirus or internet security that may block access to this server ...

74.208.10.249 gs.apple.com

i did get it to install fine with that, the only problem now is that I have NO CARRIER

It downgraded it and now the phone has lost signal. How can I update to 4.3.3?

WORKED FOR ME AS WELL!

Join the .ipsw custom 4.1 firmware Part1 and Par2 with a program called HJ-Split (www.hjsplit.org) free and easy

use iREB to put it into Pwned DFU mode
Go to iTunes (I used iTunes 10.2) and press SHIFT+Restore and find the joined .ipsw

follow the steps to jailbreak and unlock

I'm using my iPhone 3GS it's jailbroken (untethered) and unlocked with Walmart Family Mobile (which is actually T-Mobile but you get a cheaper family plan when you sign up at Walmart) and my GPS is working perfectly

Version (firmware version) = 4.1 (8B117)
Modem Firmware (baseband version) = 06.15.00

Also IF YOU ARE CONCERNED ABOUT THE IPAD VERSION IT CAN BE DOWNGRADED FOR THE 3GS TO 5.13 check Google however I haven't done it yet

I followed the steps and my iphone 3GS finally stuck in DFU mode and stuck in black screen. tinyUmbrella, fixrecovery, and recboot don help. Can someone help??....

Cannot reboot, cannot restore to 4.3.5 or any version with itune.

PLS HELP!!!

this is really work
the secrect is their firmware,part 1 and part 2
this only work with their firware
thank you for geniue work,

OMG this actually works. Thanks for the awesome guide. 3GS 06.15 Unlocked!

So you went from baseband 5.16.02 to 6.15.00 AND you GPS still works? really????

can this all be done on my mac?

Worked excellent for me as well! Awesome guide fellows

it works. was on 4.3.5 now back to 4.1 no need to jailbreak it its already jailbroken. Thanks limera1n.cc

I had the same problem as anon on August 17, 2011 6:05AM. After switching to a different computer, I finally got it to work and go to 4.1 but I wasn't getting any service so I tried using redsn0w but it doesn't recognize the ipsw. I tried to skip that step and just tried to unlock but that didn't work so I'm stuck with no service. Sorry I'm missing something easy but can someone comment and help? How can I get service and keep my iphone 3gs to stay at 4.1?

Worked perfect. No need to upgrade to 4.2.1 in Step 3 guide. Only download 4.2.1 to use it with redsn0w and extract the 6.15.00 ipad band. Also, for step 4. It is not necessary to upgrade to 4.3.2, just install ultrasn0w as instructed. Hope this helps. Also.. GPS works the custom 4.1 seems to be doing a great job.

Works perfectly perfectoooo!!!!!!!!! wooootrrraaayyyy thank you gigs.

Works Perfec! Thanks

New phone, 4.3.5/05.16.02. Downgrade worked fine, it is already jailbroken with Cydia installed. So my phone is now running 4.1/05.16.02 - but with NO CARRIER and no way to unlock it. Which means that while this device can now be many very cool things, it is not, strictly speaking, a 'phone' anymore.

1. THE 05.16.02 BASEBAND CANNOT BE UNLOCKED USING ULTRASN0W OR ANY OTHER TOOL. Wifi works fine, but the ONLY way to recover basic phone functionality is to upgrade the baseband to 06.15.00, which WILL DISABLE GPS (because the 06.15.00 bb is for the iPad, which does not have GPS). You will still have some A-GPS functionality, as the iPhone uses additional data sources such as cell-phone towers (which are aware of their own locations and the locations of various satellites) to speed up and refine location awareness. This is great when you are in the city and there are cell towers everywhere, but when you need to rely on actual (slow, battery-draining, talking-to-faraway-satellites) GPS, you will get NOTHING and we will be reading about how you died in the desert because your damn phone's GPS wasn't working.

2. IF YOUR PHONE IS ALREADY UNLOCKED, THE CUSTOM FIRMWARE USED IN THIS PROCESS WILL *LOCK* IT, so if you are thinking that problem #1 doesn't apply to you because your phone is already unlocked, think again. There is no way to stop this, it's the way the firmware was compiled. Once you have used the process on this page to downgrade to 4.1 fw, the ONLY way to get your phone unlocked and working is to "upgrade" the bb to 06.15.00, which will disable your GPS, or restore your phone to the newest firmware (or any firmware you have blobs for, 4.3.3 or higher) using iTunes. The Dev Team believes that it should be possible to downgrade the bb from 06.15.00 back to below 05.14.02 (where Ultrasn0w still works) but they are busy working on other things (like ways to jailbreak 4.3.4+) and this bb downgrade may never appear, so I'd take any advice along the lines of "upgrade your baseband to 06.15.00 and wait for a downgrade tool to appear" as being worth approximately bupkis.

3. IF YOUR 3G SERVICE IS ALREADY ACTIVATED , THIS CUSTOM FIRMWARE WILL *UN*ACTIVATE IT. Again there is no way to stop this... Pwnage Tool has an option to 'hacktivate' the custom firmware, which unfortunately was SET by whoever compiled the custom firmware... this completely KILLS all phone functionality on phones that have already been activated with AT&T. Restoring to 4.3.5 will resolve this issue, again with the loss of all jailbreak functionality.

4. DOWNGRADING TO 4.1 FW CAUSES BATTERY DRAINAGE PROBLEMS because the 4.1 and 4.2.1 IPSW continually look for valid push certificates by whatever method is available to them, wifi or cellular data. There is a fix and an explanation at http://bit.ly/e0ySDc but this isn't going to be the only problem that arises from running 4.1 fw with the 06.15.00 bb that it was never designed to operate with.


The good (?) news is that jailbreaks (unlike baseband 'upgrades') really ARE temporary - make sure your HOSTS file isn't redirecting Apple's servers, fire up iTunes, and restore your phone to the newest firmware and everything works fine again... except for the thousands of jailbreak programs that let you use your fancy smartphone in all of its glory, rather than the crippled subset of programs Apple has deemed ought to be 'enough' for anyone who is okay with them making decisions about how you are allowed to use the things you ostensibly own, a decision that makes as much sense as Texas Instruments telling you that there are certain numbers you are not allowed to add together on their calculators.

will this work even if the iphone is not activated?

ALL DONE THX

oohh !!
IT WORKED !!
Thank You So Much !!

just followed the steps :)

SO: this works fine for people who do not mind moving to the iPad baseband and losing their GPS functionality... I'm not one of those people. BUT: if I can get my phone back to 4.1, can I use redsn0w or something to UPgrade it from there to 4.3.3 (or something)? This would be the same as if I was doing a normal upgrade, so I wouldn't need blobs (that I don't have anyway)... does anyone know if there are dangers I should be aware of before attempting this?

Hi, Need Help very badly! I bought an iphone 3gs with 4.1 which is unlocked to work on all the carriers. I tried to update to 4.3.5 not knowing that a jailbroken mobile shouldn't be updated through itunes. But I did it. and the result is the update failed and restore is not working and always showing a popup stating unknown error 1015. My friend told me that Apple caught the jailbroken mobile and blocked it.
Have no idea what to do. Please help!

Thanks a lot! It worked. I nearly burst out into tears seeing my working iphone after a week.

Worked on 3GS under Windows7 x64 the following way:

1. Merge the split firmware with this: www.hjsplit.org
2. Put your device in to DFU mode using iREB
2. Flash the 4.1 custom firmware (already jailbroken) with iTunes (shift + click RESTORE)

Stop here unless you'd like to unlock the phone

3. If your baseband is not 06.15.00 than you have to flash it to 06.15.00 using this guide : http://www.limera1n.cc/2011/04/unlock-432-iphone-4-3gs-ultrasn0w-122.html
4. And to unlock finally: http://www.limera1n.cc/2011/04/unlock-432-iphone-4-3gs-ultrasn0w-122.html

This is the only solution that has worked out of about 10 I've tried.

Unlocked 3GS with upgraded BB to 06.15.00. Downgraded succesfully from 4.3.5 to 4.1

I just did this on a Mac:
1: Enter pwned DFU-mode through Red Snow
2: Use pwnagetool to make a custom iOS 4.1 firmware
3: Restore to the new custom 4.1 firmware in iTunes
4: If step 3 is successful, unlock your phone with ultrasn0w through Cydia.

It works!

Sone with it. But after that, When I inserted a simit shows "No Service" at signal tower. I cant make calls. When ever try it says call failed.
Please help! I dont have wifi internet to download anything from cydia.

Worked perfect! Got it on first try...make sure you d/l all the files in the link. Went from 4.3.5 to 4.1 no problem!

Hey guys this method works, however i bricked 2 phones (Both 3GS 8gb) recently using this method. I used this method on tons of iphone 3GS 16/32 gigs and some 8gbs but i believe the reason why it bricked was because the 3GS 8gb phones were recently made from the factory with 4.3.5 installed and both times I tried using this method, the infamous NO WIFI/NO BLUETOOTH/NO BASEBAND issue came about. I believe that if the 3GS 8gbs were older ones when they were just comming from apple, they are safe from this issue. However both the phones I bricked were pretty much bought within the last month and these were two different ocasions. Ive done unlocked/jailbreaking for a long time and these two times were the first I have ever bricked the phone. Everything other time has been good. Please be cautious.

I get a 1600 error when flashing the 4.1 custom IPSW in itunes. What do I do?

Worked Perfectly as Described, just followed steps and Done!
Was running 3GS with 4.3.5, Now on 4.21 with iPad baseband..
Many Thanks guys :)

I'm having trouble with the ipsw file. It's a valid zip, but iTunes doesn't like it and neither does PwnageToo.

Im stuck on step 3. Redsn0w tells me:
Unable to recognize specified IPSW.

Any help? I downloaded 4.2.1. that indicates the guide, but wont work.

can anyone tell me if ISO5 will serve as a remedy for 4.3.5 and BB 5.6.02? I really cant deal with battery drainage and would need my GPS if ever I were in a desert.

billionsssss of thanksssss..
i had stucked in black screen dfu mode for a week, i tried hundereds of ways but finally i made it through custom 4.1
u never get 3194 error with ios4.1 apple has still sign this ipsw.. thanks you limera1n..

i too now have 'bricked' NEW phone, due to the iPad 6.15 BB .. i have no idea what to do :( any1 managed to fix this yet ??

What website can I use to combine the files using a Mac? Please, I've been trying for a week to unlock my iPhone 3GS and I really need this to work!

Just a recap from someone who's never JB'ed their iphone before and is a complete n00b to this stuff. This guide works. I have a 3GS that had 4.3.5 with 5.16.2 baseband. DL'ed the files on this page, used HJSplit to merge the 2 files.

Followed the JB part using Redsn0w 0.9.6b6 and 4.2.1 to extract the ipad baseband. From my experience if you just downgrade to 4.1, you lose carrier service and effectively just have a brick. You have to continue with the JB, and then DL ultrasn0w. Everything works now include GPS.

Hi,
Thanks for sharing such grateful blog post. I really happy with reading your blog post. keep it up regular manner post.

On OSX you could download java version of

http://www.hjsplit.org/java/

and start it from command line:

localhost:Downloads user$ java -jar hjsplit_g.jar

or double clicking the .jar file in finder.

In commandline also:

cat file1 file2 > joined_file

might work.

Just verified that on osx:

cat iPhone2_1_4.1_8B117_Custom_Restore.ipsw.001 iPhone2_1_4.1_8B117_Custom_Restore.ipsw.002 > iPhone2_1_4.1_8B117_Custom_Restore.ipsw

creates the exact same result file that hjsplit.

I LOVE YOU!!!!!!!!! u are my hero. i have a iphone 3gs it was 4.3.5 and 05.16.02 and i just down graded it. turned back on! i love u i love u i love. btw im completely new to this. first timeever with an iphone and unlocking or jailbreaking whatever and im half way down. YES im bomb n so r u!!!!!! thank you sooo much dont ever stop helping ppl with this so frustrationg

Ok downgraded to 4.1 and jailbroken. But redsnow stops at waiting for reboot , i ve changed usb ports and still nothing any advice

works fine ,just follow the steps
thank you guys,great job
greece

I was having an issue with my iPhone 3Gs because I was trying to restore with 4.3.5 ipsw and was giving me the error "3194". I use the guide here and now my iPhone is running perfect with custome 4.1. Thanks :D

I have my iPhone back!!! Thank you guys! Took me a long time but did it! Just read the steps and follow. Good luck!

can anyone tell me if this works on iphone4 please?

I dont understand step 2

using redsn0w 0.9.6b6 but got "Unable to recognize specified IPSW" Can not do any step, please any advise.

Thank you so much.It worked for me.:-)