***WARNING***Be careful updating to iOS 5 on your 3G first generation iPads.
iOS 5 seems to be full of bugs. First we had the Newsstand app which can be dragged into a folder and rendered unusable until dragged out, additionally we had the iPad 2 being able to be unlocked with a Smart Cover bug, and now we have first generation iPad (3G models) being bricked when trying to install the iOS 5 update.
If you have an iPad 2, you shouldn't need to worry about this issue, however anyone using an iPad first generation (specifically the 3G model) will want to take into consideration that there is a massive bug with the iOS 5 software update. There is a bug causing the iPad first generation to become bricked – or unusable – after the update to iOS 5. As of late, the exact cause for the problem is unknown.
The iPad fails to restore after trying to update from iTunes – giving the user an error code (1) after restoring. The iPad then refuses to turn on correctly. After consulting with Apple, it seems that the problem is a hardware failure not accepting the new firmware onto the device. The only solution at this point is to consider buying a new iPad, or to just wait it out and see if there comes a fix anytime in the near future by Apple. Both situations are very inconvenient – but if you have an Apple retail store near you, I would suggest trying to bring it in and see if they can't replace it or fix it there. If you're covered by your AppleCare warranty still, then you shouldn't have too much trouble just bringing it in and getting a replacement.
The fix for all problems is usually to put your device into DFU mode and try restoring again, doing this is usually fail-proof on iOS devices because DFU mode is basically a switch telling the device to set everything back to default settings as if the device were shipped from the factory all over again. The DFU mode restore will not work under this circumstance and it's leaving iPad first generation users flustered with anger about the whole ideal.
Apple's customer service has usually been very good in the past but it seems that it's weakening. Numerous iPad first generation owners are phoning into Apple to get answers about this problem and they are getting nowhere, but with a response that seems to mirror the rest of the people that are complaining. Apple just says that it appears to be a hardware failure. They don't offer very much insight on the problem, or offer any way to fix it. They best you can do is wait for a fix. My recommendation to you is that if you have this problem and Apple isn't being very delightful with helping you resolve it, keep calling in about the problem. Just keep on it. After enough volume of calls, Apple will work on the issue and attempt to roll out a fix for the problem.
Are you having this issue or do you know anyone having this issue? Share a comment below! If you've found a fix for the problem, comments of that nature are welcome as well!
EDIT: MuscleNerd reports on Twitter that using Redsn0w's recovery fix option will fix this issue. If you are plagued with this problem, try that.
Sources: Cult of Mac