I believe that once the progress bar on the phone appears and iTunes has finished sending the actual data to the phone, that's the best time to ensure you're bricking it -- unplugging and holding power/home at this part should end up with a phone stuck in DFU mode.

Is there anything else we can do to "brick" the phone 4 besides unplug it while doing the restore?

Becuz for me all it does is take the phone back to the usb/itunes (plug-in illustration) on the iphone screen which is deja-vu i might as well be Denzel trying this shit over and over again.

Does the same concept of unplugging work for jailbreaking during the NOR to otherwise brick this thing?

It should. You can do the same while it's flashing the NOR during the jailbreak. You can also create a custom ramdisk that is corrupt and flash it to the device, which will end in a brick. That's a lot more in-depth though, so try to pull the plug on the jailbreak during the NOR flash. I'm fairly certain this will kick you into brick.

All very easy to say, I already tried 'to disconnect the USB cable during a software update that during a jailbrake, but to no avail. Could you explain better how do you create a RAM disk and what software I use to create it?

Originally Posted by n1ckn4m3

It should. You can do the same while it's flashing the NOR during the jailbreak. You can also create a custom ramdisk that is corrupt and flash it to the device, which will end in a brick. That's a lot more in-depth though, so try to pull the plug on the jailbreak during the NOR flash. I'm fairly certain this will kick you into brick.

There are a few posts about this here, but this covers just about everything you'd need:

Mostly iPhone hacking: Working iPhone recovery ramdisk with SSH ;-)

Buy a cheap usb to iPhone cable at the dollar store cut the usb end off strip the wires and give er 12 volts from a car battery or 30 / 40 vdc from a tyco train transformer it will not turn on ..... trust me

Originally Posted by padrickd

Buy a cheap usb to iPhone cable at the dollar store cut the usb end off strip the wires and give er 12 volts from a car battery or 30 / 40 vdc from a tyco train transformer it will not turn on ..... trust me

Sure, it will break the phone -- it's also one of the things that is very easy for Apple to check for. In most cases, overvoltage to the point of blowing chips in the phone is NOT covered under warranty unless you bring in the power supply as well and can show that it exhibits the same behavior...