i need to sell my 8gb iPhone 3G and i'm trying to do what it says in the thread title

the only thing that seems to work is downgrading it to 3.1.3. I still get the 1015 error when the restore is complete, but I can use TinyUmbrella to kick it out of the restore and it then works absolutely fine.

If I try to then update it to 4.2.1 then I get the 1015 error and I can't get it out of the restore loop no matter what. I try downgrading to 4.1 and get an error code of 14 and it doesn't even manage to get a quarter of the way through the restore cycle.

Been trying dozens of different ways since this afternoon but i'm just wondering if I just need to accept defeat and put it on ebay advising that it's been previously jailbroken and happily works on 3.1.3 but nothing else ?

Sorry if I'm missing something here...

Have you tried plugging it in and selecting 'Restore' in iTunes?

Yup, done that as well.

I think it's something to do with the fact that I used redsn0w to unlock it and it used the iPad baseband, which can't be rolled back unless you've got an early version bootloader apparently.

If i want 4.2.1 on it i think i have to find a custom firmware

it just means overall that i won't be able to take it to CEX which is what i mainly wanted to do as they pay the best price for them

Depends if anyone in the store knows what they're doing with them. My store used to sell them JB unlocked but we did it ourselves. Could just Mazuma it? I got more than CEX's Unlocked C with them.

Mazuma etc also take the phone in pretty poor condition that a CeX store might F it for, for an iPhone i'm talking plastic cracks, dust under screen etc.

hhmm .. didn't think of mazuma. i'll check them out - cheers

They're offering £82 at the moment, can get more with a grade C from CeX if you get yours up and running again.

Does yours have any cracks in the plastic casing? If so CeX wont take it. Mazuma took mine and I could see through the top of mine, and pull the back casing up cause it had a massive splinter crack from the dock haha.

wow that's a result in that condition !

mine will only work on OS 3.1.3 - i was up until about 3:30am this morning figuring that out.

If you update it, it screws up so I doubt CEX would ever take it. Cosmetically, it's actually quite good. No cracks or marks and the reverse of it is hardly scratched as well.

I've got one more thing to try today but if that doesn't work I think i'm just going to try Mazuma, and i'll probably put it on eBay at the same time and maybe put a starting price of £82 quid just for the hell of it

ok that one more thing turned in to 2 more things but still nothing worked. so that's that. i'm going to restore 3.1.3. to it and get in touch with Mazuma, as well as putting it on eBay.

I do need about £80 quid for it so Mazuma would be ideal.

well it's done. took it to a branch of cash converters and they offered me £70 quid for it which i gladly accepted. said nothing about the restore issue. i s'pose it's entirely feasible that I could have bought the phone 2nd hand and never once restored it myself.

that's my excuse anyway !

I just thought it would be better to take £70 now than wait a few days fannying around with mazuma or ebay.