Iphone 3gs old bootroom 3.1.3 not in jailbreak

Hi,

I have the following scenario :-

- Iphone 3Gs 3.1.3 ( officially locked old bootroom )
- baseband 5.12.1 - it was jailbreak but no SHSH on file ( updated to 3.1.3 via Itune from apple )
- I have manged to get 3.1.3 SHSH on file using TinyUmbrella.

I need to restore using custom IPSW but I'm always getting 1600 error.

Any suggestion ..

thanks for the support ;)

Search the forums, this has been documented many times.

Spirit does not pwn the LLB so a spirit jailbroken phone cannot restore a custom firmware. The LLB must be pwned on a 3GS in order to restore custom firmware. You can fix this, read about it here:

Mostly iPhone hacking: OLD BOOTROM + Spirit => 4.0 JB