Should I have been able to do this?

[nfrederick]

I had upgraded to 4.2.1 just wanting to check it out thinking that I had my SHSH blobs saved for this device. Turns out the 4.1 SHSH blobs I had saved was for my other iPhone 4. So naturally trying to downgrade back to 4.1 yielded not so great results. But I was like what the hell, I fired up tinyumbrella on my MacBook and was looking around in it a bit (only have used it to save SHSH blobs on other iPhone) and figured I'd try to restore with those blobs and just see what happened. So I clicked start TSS sever or whatever and went back to iTunes and then tried to restore back to 4.1 again. Everything appeared to be working just fine, but when my phone got to the end of the restore where the progress bar was almost done iTunes said restore failed and some other garbage. Now my phone was dead, I turn it on and the Apple logo appears for a few seconds then goes right to the connect to iTunes screen, but when I connect to iTunes it says it has detected a device in recovery mode and I have to do a restore in order to get it back up and running. Every attempt to try and restore from there failed. So I fire up tinyumbrella again and notice I can click on exit recovery or something like that. So I click on it, brings the progress bar that it had error'd on back up and finishes the restore. Now I'm back on 4.1 jailbroken and everything is running smooth like butter. Should I have been able to do all this? I didn't think that SHSH blobs from one iPhone would work for another. And I know for a FACT that the blobs I used where not for the device that I had restored.

Basically, will SHSH blobs saved from one device work for another as long as it is the same model.

/end long confusing story

 

[myzhi]

SHSH blobs are unique to each device and firmware version. You can't use it for a different phone or firmware. When did you restore to 4.1? Did you do it when Apple was still signing 4.1? That's most likely the reason. And, the error at the end is probably because the baseband failed to changed. On IP4, Apple has security SHSH checks on both firmware and baseband. Thus, you need TU's "Kick it out of recovery" option.

 

[nfrederick]

I did this last night at around 10PM CST, and as far as I know, Apple has not signed 4.1 for a number of days now.

Info from about screen AFTER restoring back to 4.1 from 4.2.1

Just a few of what I think is important

Version 4.1 (8B117)
Carrier AT&T 8.0
Model MC608LL
Modem Firmware 03.10.01

 

[myzhi]

I did this last night at around 10PM CST, and as far as I know, Apple has not signed 4.1 for a number of days now.

Info from about screen AFTER restoring back to 4.1 from 4.2.1

Just a few of what I think is important

Version 4.1 (8B117)
Carrier AT&T 8.0
Model MC608LL
Modem Firmware 03.10.01

Use TU and download the SHSHs for the phone. Is 4.1 there? And, error at the end of restore is definitely because the baseband could not be change from 3.10 to 2.10.

 

[nfrederick]

So is it bad that I have 3.10 instead of 2.10?

I don't ever need an unlock.

 

[nfrederick]

And it says under All Saved SHSH's for Nate's iPhone:

iphone4 4.1 (8B117)-3344724571533 <------- what is that number mean?
iPhone4 4.2.1 (8C148)-3344724571533
iPhone4 4.2b3 (8C5115c)-3344724571533

Also, my device name is not Nate's iPhone, that was my other iPhone 4's name in iTunes. This one is totally different.

 

[myzhi]

So is it bad that I have 3.10 instead of 2.10?

I don't ever need an unlock.

If you don't need unlock, it's better to have the newer baseband. In most cases, Apple only fixes exploits, but in same case, they do fix / improve network / signal issues.

And it says under All Saved SHSH's for Nate's iPhone:

iphone4 4.1 (8B117)-3344724571533 <------- what is that number mean?
iPhone4 4.2.1 (8C148)-3344724571533
iPhone4 4.2b3 (8C5115c)-3344724571533

Also, my device name is not Nate's iPhone, that was my other iPhone 4's name in iTunes. This one is totally different.

That's the device unique ECID number. Is that the device you are confuse about? If not, in TU, on top right, under "Recent Devices," click on the phone you are questioning about, in middle window, what firmware are listed for "Saved SHSH?"

 

[nfrederick]

4.1
4.2.1
4.2b3

I guess I did save my SHSH then. But why did it go ape**** during the restore, i fired up TU, started TSS server, went into iTunes, did a option+click and chose the 4.1 restore ispw and it went crazy after that, is it becuase 4.2.1 upgraded my baseband and while trying to downgrade back to 2.10 it couldnt and froze up?

This all seemed much easier back in the days of the 2.x, 3.x firmwares, which was the last time I had an iPhone. I have since returned from the world of BlackBerry and Android.

 

[Ipheuria]

from what I read through the thread yes the problem was because it was unable to downgrade your baseband since you're now on 4.1 but your baseband is still the new baseband.

 

[myzhi]

4.1
4.2.1
4.2b3

I guess I did save my SHSH then. But why did it go ape**** during the restore, i fired up TU, started TSS server, went into iTunes, did a option+click and chose the 4.1 restore ispw and it went crazy after that, is it becuase 4.2.1 upgraded my baseband and while trying to downgrade back to 2.10 it couldnt and froze up?

This all seemed much easier back in the days of the 2.x, 3.x firmwares, which was the last time I had an iPhone. I have since returned from the world of BlackBerry and Android.

As I already stated early, Apple implemented checks on both firmware and baseband on IP4 (only). The SHSH files only apply to the firmware. We can restore the firmware, but it will cause an error fail on restoring the baseband because it can't pass the baseband check at the very end of the restore process. Thus, you can use TU's "Kick out of recovery" mode to reboot the phone because the OS was still installed on the phone. But, this only works on 4.0-4.1 firmware. I believe Apple fix this workaround by having the OS checks for baseband update in 4.2.1. So, TU's "Kick out of recovery" mode no longer works.

 

[nfrederick]

Noted, thanks for the help guys.