iPhone 3G will not go in to DFU mode

[ct0wn]

Hello..

I have an old iPhone 3G that I just put 4.2.1 on and I'm desperately trying to get it in to DFU mode so that I can jailbreak it. No matter what I do it just boots up normally.

I have 3 other iPhones laying around here that go in to DFU mode just fine so I'm pretty sure its not my method. The home and power buttons seem to be working just fine when the phone is powered up. I have tried different USB cables and different computers. Nothing I do will get this phone in DFU. I have read all the guides and watched all the videos..

Any suggestions??? THANKS!

Ok I finally figured this out. I managed to jailbreak 4.2.1 on my iPhone 3G without putting it in to DFU mode using the hardware buttons.

Hopefully this will help someone else out in the future. Here is a list of the steps I took took to make it happen. I'm not going to list all the gory details, they are available on google.

1. Append 'hosts' file on my computer to reflect Saurik's cache server
2. Upload corrupted 4.2.1 firmware to phone (AppleLogo -> LLB)
3. Upload official 3.1 firmware to phone
4. iReb
5. blackra1n
6. Upload pwned 4.2.1 firmware to phone

jailbreak success!

[Broomhead]

Congrats. I'm sure this will be useful to others. Thanks for sharing the solution.