About to buy a 3GS, need advice

[Five0nIt]

So i'm going to buy a 3GS for my sister for xmas. It's on firmware 3.1.2. What 4.x firmware can i update too that is safe to jailbreak and unlock? Thanks.

[Stray]

4.0.2 is the highest that you can do. Unless you can get a custom 4.1 firmware from somebody to preserve your baseband.

[Five0nIt]

well i tried to make a custom 4.1 fw with snowbreeze, but i keep getting an error when i try to restore the phone with it.

[i.Annie]

You need 4.1 SHSHs to restore to a custom fw. Either check your SHSHs and see if you've got 4.1 or create a custom firmware for 4.2.1 with PwnageTool. If you don't have a Mac, you'll have to find the custom fw online.

Note, if it is a new boot device, and you don't have SHSHs, you'll be forced to 4.2.1 and have a tethered jb. Read this here and it will tell you how to figure out if you've got SHSHs and which bootrom you have.

click here for details

[Five0nIt]

i dont have a tethered jailbreak or the shshS, or a mac. Know where I can find the 4.2.1 FW?

[i.Annie]

You'd have to Google for the custom fw or find someone here on MMi who can send you a copy. We can't post links or downloads of custom firmwares here.

[customworksking]

keep it on 3.1.2 IMO!