Q: iPad 4 won't restore. Unknown error 3004.

Perform a "hard reset" on the device by pressing down and holding the home button and the sleep/wake button for up to 30secs. until you see a black screen with the Apple logo, then release.

Then test to see if it solved the problem.

This is a common scenario. Why are you angry at Apple for your cable disconnecting and interrupting the process?

3000 series errors mean iTunes cannot connect to the update servers. Follow these instructions to restore from recover mode. Be sure to follow the steps precisely.

One last thing. If you are on Mac, read the instruction in the link I gave you. You may be able to resolve an error 3004 by quitting iTunes and using the following command in the command line: dscacheutil -flushcache.

I agree with the first post from Bryan1331 as I'm getting tired of Apple posting updates that completely hose your system.  I tried to updated from 6.03 --> 7.03 which it kept prompting me to update.. Now I'm stuck in recovery mode with no way out. 

I've disabled firewall, SAV,  and everthing else I can think of along with uninstalling iTunes and reinstalling itunes (latest)... updated my Win7 workstations with any available patches.. and even downloaded the iPad2.5_7.0.4_11B554a_Restore.ipsw and tried to restore using the "shift click" on the restore and it extracts the file but it seems like when it's trying to verify this with Apple --> it promptly returns the 3004 unknown error and I've been stuck at this point for 1/2 a day now.... really starting to tick me off.  

Anyone else have any tips they can provide? 

If Your iPad Stuck On Recovery Mode (itunes Logo) You Can Fix It By Following These Steps :

1) Download Tongbu Assistant On Your Computer

2)Open Tongbu Assistant And Go To The Home Section

3)When You See Your Device Connected Press On The "Exit Recovery Mode"

4) Wait A Moment

5) Enjoy

No Need To Thank Me But Sharing Informations To People Is Nice And Its Nicer When You Dont Know The Person That You Helped

<3 <3 <3

I LOVE YOU YanesShater. Greate WORK. the iTune was killing me, firts error 3194 then error 11 then i download this program and then another one, i downloaded ios 7 two times. Thanks a zilion.

But I am still in safe mode can I restore my device with "Tongbu Assistant" ?

1.Turn off your device. If you can't turn it off, press and hold the Sleep/Wake and Home buttons at the same time and wait a few seconds for it to turn off.

2.Plug the device's USB cable into your computer only.

3.Hold down the device's Home button as you connect the USB cable to it.

4.When you see the Connect to iTunes screen, release the Home button. If you don't see this screen, try steps 1 through 3 one more time.

5.Use iTunes to restore your device.

Additional Information:

If you started your device in recovery mode by mistake, restart it to exit recovery mode. Or you can just wait—after 15 minutes the device will exit recovery mode by itself. If you want a faster way to fix iPad stuck in recovery mode, try iPad data recovery software.

Thanks @ternenceswift

the same issue, I used this tool  iPad stuck in recovery mode  solved this issue.