Help with jailbreaking and Cydia for iPhones, iPads, and iPod touches.

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How to fix some mysterious problems.

I have an iphone 4 direct from apple, so it's unlocked from the manufacturer. I am on software version 4.2.1 (8C148) and am currently using the tethered jailbreak with redsn0w 9.6b4. I have tried running Greenpois0n straight over my jailbreak, but it just finishes in about 10 seconds saying "Jailbreak failed". I've tried restoring to a non-jailbroken 4.2.1 but it won't restart after doing that.

Please help!

asked 09 Mar '11, 23:13

ericjon97's gravatar image


What do you mean by it won't restart after restoring to 4.2.1?

(09 Mar '11, 23:14) spockers ♦♦ spockers's gravatar image

Are you on Mac or Windows?

(09 Mar '11, 23:15) spockers ♦♦ spockers's gravatar image

After Jailbreak fail message, try to start your phone by holding the power and sleep buttin together for 10 seconds until the apple logo appears and then let go, if this fails to start you phone properly, then put your phone in DFU mode and restore to stock 4.2.1 in iTunes.

Check this good YouTube for entering DFU just skip the sarcasmic detailed language by @KOI2281

For the failing greenpois0n, the following tips will help:

  • Must have iTunes 10.1 or later installed
  • Must have good internet connection to download 2 files with total 5MB size
  • Must delete the temporary files created during previous runs of greenpois0n, these should be in the same folder where greenpois0n is running from, their names start with iBSS and kernelcache

If this keeps failing, you can try sn0wbreeze ( for Windows or PwnageTool ( for Mac


answered 09 Mar '11, 23:24

knightz4u's gravatar image


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Asked: 09 Mar '11, 23:13

Seen: 3,467 times

Last updated: 09 Mar '11, 23:24

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