If you are still having problems, could you let us know what the phone is doing? Is it on a continuous black screen or when it boots does is show the Connect to iTunes screen with no emergency call swipe option? Either way, dont panic - you should still be able to recover you phone.
Let me know,
BTW: You can only restore to custom IPSW's once you have upgraded to the iPad baseband.
The challenge that you have is to properly get your phone into DFU. As you know, in its current stage iTunes cannot restore it. Although we will follow the similar approach indicated by the RedSn0w software to enter DFU, we have to modify the instructions slightly and that is what I have written below. Because you have the iPad BB installed, from here on out – you will ALWAYS have to restore your phone with a custom IPSW file – the custom IPSW omits BB checks and updates and hence will allow iTunes to perform a restore without resulting in errors due to device compatibility. Before beginning the following instructions, use RedSn0w to create a ‘Custom IPSW’ so you can restore to it later.
I’ve been in the same boat as you recently and after I recovered my phone I went ahead and wrote down these instructions:
Phone (3GS) Stuck @ RESTORE ITUNES PLUG SCREEN
Symptoms: When turned on or connected the phone shows the connect to iTunes screen with no emergency call slider. iTunes sees phone in recovery but phone cannot be restored
Cause: Could be caused by an incomplete restore or the wrong boot rom selected when the custom ipsw was created.
Tools & Files Needed: RedSn0w, stock IPSW for your device from Apple
Grab the latest version of RedSn0w from here (0.9.10b5):
Use this list to identify and download a non-custom IPSW's directly from Apple (the 3GS one should be ‘iPhone2,1_5.0.1_9A405_Restore.ipsw’):
Putting phone into PWNED DFU mode:
1. Connect the phone to your computer - this should turn the phone on and show the Apple logo and proceed to the plug into iTunes (no swipe) screen.
2. Launch RedSn0w and select 'Extras'. Select 'Specify IPSW' and select the stock IPSW which you downloaded from Apple. You will be prompted to select the appropriate boot-rom option (yes ='s New, no ='s Old). In your case, select ‘YES’.
3. Select the 'PWNED DFU' option. As mentioned, the RedSn0w instructions for entering into DFU need to be changed slightly because in its current state your phone cannot be shut down completely because it continues to reboot once it is off. So to enter DFU perform the following steps:
a. Leave RedSn0w in the initial PWND DFU screen and do not click Next – we will click Next in a minute.
b. Hold the power and home button till the phone shuts off (phone screen shuts down).
c. Release both buttons and quickly press and hold the power button.
d. Count to three and press and hold both the power and home button together.
- At first the Apple logo will be on the screen followed by the iTunes plug screen. Wait till the screen turns off and count to three and release the power button but keep holding the home button.
e. While holding the phone and home button with one hand, use your other hand to click on the ‘Next’ button in RedSn0w. It should recognize DFU immediately and begin the needed exploit. PWNED DFU should happen relatively quick and RedSn0w will say that it is ‘Done’ and your phone will have a black screen. If not recognized in DFU, RedSn0w will eventually tell you such – return to Step 3 and try again.
4. Once finished, restore in iTunes with the custom IPSW you created earlier (clicking SHIFT restore and selecting the custom file on your computer).
Best of luck – let me know how it goes!