I have some similar issues with my ipad 3 wifi. I will try to include all details in hopes of getting a solution here.
1- I upgraded my ipad from 6.0.1 to 6.1.3 on sept 17. Then I upgraded to ios 7.0 on release day sept 18th. I had no issues downloading, installing, or running ios 7 on my ipad. At first. . .
2- I started to have issues with my pad turning off suddenly after I got below 50% battery power. OR it would enter a respring if I locked my pad (clicked the power button), then clicked either the home or power button to "wake" it.
I figured that my pad was being tempermental about only having a partial charge, so I allowed it to die all the way, then recharge it to full. That is when the serious issues started!
3-My pad only made it to 10% before it shut itself off and would not power up. As in, no apple logo, no lock screen, no black screen that is actually powered on but only displaying black colors. NOTHING. So I decided to charge it and see what happened.
4- After it charged for a bit, it did start the boot process, but with a twist. It would display the apple logo for about 10 seconds, then the apple logo would dim to a grey color for half a second, then turn off. Then the process would repeat. This loop would repeat itself whether my pad was plugged in to a power outlet, Mac or PC, or unplugged entirely from anything.
(For thoroughness, I tried all of the steps above and below on a PC and on Boot Camp Windows on my Mac. I have gotten slightly varied results, depending on the machine and OS. I will try to remember to detail which events occurred on which machine\OS)
5- Iplugged my pad into my iMac, with Itunes opened, and hoped to do a restore. But Itunes wouldnt recognize that my pad was plugged in. So I put the pad into DFU mode. (my pad now apears to be powered off) NOW Itunes recognizes it. It prompts with the message "Itunes has detected a device in recovery mode, you must restore it. . . " So I clicked the OK button, CLicked the Restore Button in the "Ipad" window, CLicked the Restore and Update button, and waited for Itunes and my pad to sort things out.
6- Itunes extracts the ios 7 software, says several things in the progress bar across the top, my pad starts to boot by showing the apple logo, itunes says it is waiting to verify restore with apple, my pad is showing the apple logo with a dark grey bar below it which indicates the amount of progress to be made before the restore process is completed. BUT, the pad turns off before ANY progress begins. And itunes displays the "An unknown error has occurred. error 9"
7- My pad is now showing the apple logo again for 10 seconds, and Itunes is no longer displaying that my pad is plugged in. Shortly later, my pad shows the Blue Itunes logo with the image of the usb cable (restore mode). In order to get Itunes to recognize my device again, I have to unplug and replug my pad. Which starts the prompts of "Itunes has detected a device in restore mode. . . " so on, so on.
One slight variation to all of this is, if I leave my pad plugged in after the failed Restore process (itunes no longer recognizes that my pad is plugged in), after about 5-10 minutes my pad will show the apple logo. Itunes now redetects my pad and asks to go through the restore process again. But the result is the same ---> error 9.
(on my pc machine, the error i receive is 3014, on bootcamp windows it is still error 9)
8- I have attempted to use TinyUmbrella to "Fix recovery". But it only SAYS that the fix recovery process is started and finished and to allow the device to reboot. But it never actually reboots, or does anything. I also tried clicking exit recovery. This only puts my pad back into the endless apple logo, power off loop as noted in section 4-. I also tried using the TSS server process in TinyUmbrella. This gave much different results, depending on whether or not my device was in DFU mode, or Restore mode. ---> DFU resulted in error 4014 (which is still unresolved) and Restore Mode resulted in error 11.
9- I also tried using the custom IPSW process to possibly load an older ios (with and without TinyUmbrella). But this resulted in many varied errors, usually the "This device is not eligible for this build", error 9, or error 4014. I tried ios's 6.0.1 and 6.1.3. I even tried to custom restore back to ios 7.0. Nothing new.
10- I have also tried editing, or outright deleting the Hosts files. Or any facimiles of the Hosts files located in the same directory. Nothing. Also tried deleting or altering the Hosts files in bootcamp and on my pc. Nothing.
11- I tried redownloading and installing a new copy of Itunes and the ios firmwares. Nothing new or different.
12- I have tried rebooting all of my machines. I also tried allowing my pad to charge for 1 1/2 days, just to ensure that it was not a dead battery issue. No changes.
13- Jailbreak software obviously doesn't help, because they won't recognize a device with this ios. Interstingly, my pad does seem to register as being on ios 7 in TinyUmbrella. So error 9 (some sort of vague USB issue- which is NOT the case here) seems to be inaccurate. TinyUmbrella will show EVERYTHING my device is doing. Either unplugging and plugging, restoring, DFU mode, etc. . . The USB is obviously working and allowing data to go in and out.
So, that's my recounting of this frustrating experience. Anyone have some new ideas or combinations that I haven't tried?
Hopefully, Thanks-in-advance,
Humminna