try hard reset, press home and power button for about 15sec..

enter DFU mode and use itunes to restore first. did u jailbreak?

dun connect to computer, you should know how to enter dfu mode then only connect usb..try

to restore iPhone and reset the phone to default factory settings, follow these steps:

1. Turn off iPhone - Hold down the Sleep/Wake button for a few seconds until the red slider appears, then slide the red slider. Ignore this step if your iPhone is already off.
2. Press and hold down the Home button for about 10 seconds until a yellow triangle with a text which says Please Connect to iTunes appears.

3. Plug the iPhone into Mac or Windows PC. Release the button if you haven’t.
4. Run and open iTunes if it’s not already opened yet.
5. iTunes will prompt a message that says iTunes has detected an iPhone in recovery mode. Click OK.
6. You will be taken to the iPhone pane. Then, click on Restore.
7. Wait for the full restoration process to complete, and the iPhone will be back to the original settings state as when it left the manufacturing factory, typically a working phone again if you face any problem, unless it’s hardware related

i not sure, i just took from a guide i found. but instead the triangle, should be a usb picture, showing to plug into itunes

another way u might can try is try to use quickpawn 2.1 , it might able to JB + restore back ur phone

This post has been edited by Shock: Oct 15 2008, 03:55 AM

if not mistaken error 1603/4 is the firmware not correct or compiling is not done correctlly. the only why i can suggest is use DFU mode. or hard reset, press home and power button together for 15 sec then power 2 sec

how to put it, when u do quickpawn, u no need to enter DFU mode, you only need to enter recovery mode to reinstall the firmware. that what i trying to say.