I have tried to jailbreak an iPhone 3 GS (older gen) with redsn0w, limera1n, and greenpois0n to no avail. Every single time I try to jailbreak, even though i follow all the instructions to enter DFU mode, it doesn't work. It should be displaying a white screen when I attempt to enter DFU mode, but instead it displays nothing--the screen stays black. In redsn0w it goes to "Waiting for reboot" but stays stuck there. Even if I wait five minutes it does nothing.
Any ideas?
Any ideas?