Put your phone in DFU mode. The tutorial for that is here https://forums.macrumors.com/threads/603129/
Hi,
I have the same problem, I jailbreak my iPhone 3GS 3.1.3 with spirit after reset it worked fine for few minutes and then went off. it is now completely off, I tried everything but it is not coming up, it is detected by the itunes in the recovery mode.When I am restoring it with itunes it is giving this error" The iPhone couldn't be restored, the device is not eligible for this build"
Please help I am stuck with this phone.
Regards
I did the hold power and home for 10sec
then let go of power and keeping holding down the home button til the phone gets recognize on iTunes - around another 10-15 sec.
Then it should be in recovery mode and ask you to restore and update. I just hold the shift-key (Windows) select the firmware 3.1.2 and restore
Your only option is to update to 4.0.1. You will have to jailbreak once the new Spirit comes out, which shouldn't be long.
Thanks for the comment, can I downgrade to 3.1.3 or 3.1.2 without SHSH.
Regards
No, you can only downgrade if you have your SHSH blobs signed for the 3.1.2 or 3.1.3 firmware. And it's too late now to save them.