Install unsigned IPSW

Tech Support
1

Hi All,

I upgraded my iPhone se (the old one) from 12.2 to 13.6. The upgrade went ok and everything works fine as a handset. However, now my Bluetooth connection in my car is no good, the audio comes and goes every few seconds. I assume that is because my uconnect system in my dodge is too old for this update. Everything worked perfectly on 12.2.

I’m trying to downgrade to iOS 12.4 with an IPSW file from Macpaw.com. This must be an unsigned file because Apple is rejecting the update. Has anyone tried using third party software to install an unsigned IPSW? I trust the Mac paw file but I’m very skeptical of third party bootloaders and jailbreak solutions.

Any help would be appreciated.

https://macpaw.com/how-to/downgrade-ios

2

You can download ISPW’s directly from Apple, but even then you won’t be able to install them, unless Apple is signing that version of iOS.

That article was probably valid in the short period of time after the introduction of iOS 13 when Apple was still signing iOS 13 and iOS 12…

3

Do you have your shsh2 blobs backed up?

4

Ugh, I feel your pain. My son’s UConnect Bluetooth stopped working reliably when he got his iPhone 11 and has never worked right since.

That being said, you’re not going to get that to work now that Apple has stopped signing it.

5

Thanks for the information @rob and @tjluoma.

Update: I am able to take calls over Bluetooth which was a welcome surprise. Podcasts and music still do not work. 13.6 may workout for me because the SE has the headphone jack.

@Mr.MacMyLifeUp I’m not familiar with the backup type you mentioned. I accidentally overwrote my 12.2 backup with a 13.6 backup on my main machine but I should have an iTunes backup on my wife’s Mac.

6

Are SHSH blobs still a thing?

I thought that only worked for early (ancient) iOS versions?

7

Yes they are. They just aren’t as common. You can back them up with a tool on the Mac called blobs saver. The reality is, iOS hasn’t changed that much since the old versions. It’s still the same principle to restore. If the ipsw is not signed, you still need your blobs to restore it. That’s just how iOS works, believe me, I’ve tried doing this to some of my devices, it has never worked because I never had my blobs backed up.

8

If you still have a backup on your wife’s Mac, it’s really not hard to do then. A while back, I wanted to see if some of my old backups were there, and they were. I just forget the keyboard combination to show you them.

9

I’m not sure you understand what I was trying to say?

One could only use SHSH blobs to restore older versions of iOS, before Apple added the “nonce” (see the link I shared before).

So even if you had your SHSH blobs backed up this would still not work.

Of course I might be wrong instead, but then I would like to see a success story.

10

How about a new bluetooth to car audio jack dongle?

Phone and audio are separate bluetooth functions in cars. One of ours only has phone bluetooth so we got a wired Griffin Road Trip to charge the phone and connect it to the audio jack. This works well but appears to be no longer made.

11

Thank you everyone for the input on this.

I drove quite a bit today and was able to take calls over Bluetooth and listen to podcasts through the aux port. This setup is not ideal but may be better than trying to downgrade. There are some positive features to iOS 13 over 12 which helps. Overall I’m frustrated that it’s so simple to upgrade but so difficult to go back.

I really do appreciate the help! If my current setup proves too cumbersome I may revisit the potential blobs downgrade or an additional Bluetooth device for my car.