Hi all I'm having massive problems with my iPhone 3GS. It's stick in dfu and when I try to restore with iTunes I get error 21. I have tried restoring on other computers, fresh install of iTunes etc but still no good. I have even tried recovery fix with tiny umbrella but still stuck in dfu and wont restore. Any advice would be much appreciated.
3GS iTunes error 21
- Thread starter Scoobie13
- Start date
Scoobie13 said:
We need more details.
Is it unlocked?
iPad baseband 6.15?
Stuck in Recovery Mode?
or DFU mode? There is a difference.
DFU mode is a black screen. Looks like the device is off.
Recovery mode show iTunes logo with a USB cable.
- Thread Starter
- #3
Hi it is a 32gig factory unlocked not on iPad baseband. The screen is black and I'm sure it's in dfu not recovery as when I try recovery fix with tiny umbrella it detects my phone in dfu. I have also tried ireb to pwndfu before restore and still error 21. I'm not trying to jailbreak with custom firmware just clean restore with iTunes. Many thanks.
Scoobie13 said:
Recover fix only works for recovery mode, not DFU.
PWNED DFU mode is *only* for restoring to custom iPSWs.
What I would do is create a custom iPSW with Sn0wbreeze 2.9.5 from here: ih8sn0w.com.
It's a jailbreak tool...but you can choose to not jailbreak the iPSW by choosing "Baseband Preservation Mode".
I know you don't need to worry about preserving baseband, because your factory unlocked....but this should work...and if you were already on 5.1.1 then it will keep the same baseband anyway. BB just doesn't matter on a factory unlocked phone. Preserving the baseband will do no harm.
As long as you choose Baseband Preservation Mode within Sn0wbreeze it will not jailbreak the iPSW when it's building it.
Create the iPSW, enter PWNED DFU with iREB and shift+restore in iTunes.
This iPSW bypasses the "verification" iTunes runs before restoring.
That should work.....hopefully.
- Thread Starter
- #5
Many thanks for your thoughts, I have tried jail breaking with snow breeze and redsnow. Snow breeze i still get error 21 and redsnow loads up on screen then screen goes black with white text the stops and just keeps scrolling text saying please wait and after about 5mins screens goes black then back in dfu.
Scoobie13 said:
No no no.
You can never ever ever under no circumstances change your host file.
All you have to do is change the host file back to what it was and it will work.
I knew error 21 sounded familiar.
Never change the host file. You read that from an "*extremely outdated* post.
As long as the host file is modified then it is virtually impossible to restore period until the host file is changed back to what it was.
Scoobie13 said:
Yeah sure....but you said you modified it right?
Well...whatever you added...just delete whatever it is you added,
Open the host file with note pad.
Select/highlight all content and copy it.
Now click on the Windows logo and look for NotePad in the windows bar. When you find it..right click, then click "Run as administrator".
Once open, paste into the blank notepad.
Now just delete whatever it is you added, make sure to save it C: > Windows> System 32> drivers> etc. (should do that automatically...just click save file as).
Of coarse choose to replace the existing host file.
- Thread Starter
- #11
I have modified as I read on other forums. Removed gs/apple.com lines and added one as well but I saved the lines I removed on my desktop so will change it back to as it was and try again. I did get error 21 originally before changing the host that's why I started searching for fixes.
Scoobie13 said:
Yes....I understand.
But modifying the host will get you no where. At one time it was a useful method that actually worked....but that is not the case anymore.
It's not the case anymore because Tiny Umbrella already has the modified host file in etc. that is if you have Tiny Umbrella installed. Which I doubt you do...but either way...a modified host file just doesn't work anymore.
- Thread Starter
- #13
Yes I have tiny umbrella. I have made sure my host file is as it should be unmodified still get error 21. I have also tried restoring on my friends laptop which is 100% untampered with still same error. If its any help just before iTunes error iPhone is prepared for restore it boots up to a dim screen and if a open redsnow straight away it comes up with iPhone 3GS in recovery mode then when screen goes dead redsnow say iPhone 3GS dfu mode. Could this be the problem when trying to restore its jumping from dfu to recovery when booting up.
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