I have an iphone 3g 16gb I have beed trying for days to access DFU mode but I can't due to my brocken power button.. I have tried pressing the corner to make it work but nothing I want to ask you if there is any way to fix it by opening it..I have the knowledge and I think I can do it but I dont know how..\ John

You can try Leawo iOS Data Recovery to fix this issue and it's effective in restoring iPhone in DFU mode. Just check below steps.

Step 1. Run Leawo iOS Data Recovery and choose Recover from iOS Device.

Step 2. Connect iPhone 4 to computer with USB and choose DFU in the pop-up dialog.

Step 3. Follow the tutorial and enter DFU mode on your iPhone 4.

Step 4. The program will communicate and scan your iPhone 4. When the scan is done, select the files you need and click Recover.

Step 5. Click Open in the pop-up dialog to choose a target folder on your computer to save the files. Then click Go to recover deleted files from iPhone 4 under DFU mode.

When the recovering process is done, you will get the files in the target folder. If you want to exit DFU mode on your iPhone 4, you only need to click Exit DFU Mode at the left bottom of Leawo iOS Data Recovery.

For more details, check: How to Enter DFU Mode and Recover Deleted Files from iPhone

Search google for a program called tiny umbrella.

Do a hard reset.

1. Press-hold the Home button (big circle below the screen) and the Sleep/Wake button (on top of the iPhone) simultaneously.
2. Continue holding both buttons (Ignore the "Slide to power off") until the iPhone shuts off and begins to restart.
3. You may let go when you see the silver Apple logo.
4. You have completed a hard reset successfully.
5. Don't be alarmed that it takes quite a while to load from the Apple logo to the main screen. This is normal.

If this does not work, put into recovery mode and restore from itunes.
Step One
Open iTunes and connect the iPhone to your Mac.


Step Two
Press and hold the Home button and the Sleep/Wake button at the same time.


Step Three
As soon as the screen goes black release the Sleep/Wake button. Continue holding the home button until you iTunes pops up a message telling you that it has detected an iPhone in recovery mode.


The iPhone will look like this:

Try to get the iphone into DFU mode and restore the phone from a previous backup, did you try to update to ios4?

To put the iPhone into DFU mode so you can do an iTunes firmware restore follow these steps:

Step One
Open iTunes and connect the iPhone to your Mac or PC.


Step Two
Press and hold the Home button and the Sleep/Wake button at the same time.


Step Three
After exactly 10 seconds release the Sleep/Wake button. Continue holding the home button until you iTunes pops up a message telling you that it has detected an iPhone in recovery mode.


The iPhone screen will remain black like this:


NOTE***: It may take a few attempts to get your iPhone into DFU mode. Generally, I hold down both buttons then release the Home button just before I think the Apple logo would appear. If you are still holding both buttons down and you see the Apple logo you are holding them down for too long!

If this happens, you will need to put your iPhone in DFU(Device Firmware Update mode) mode which will restore your iPhone completely. Since you wont have any other option, you will have to go for this option or else your iPhone will remain in this bricked condition for ever.

easy steps-

1. You need to first connect your Apple logo stuck iPhone to iTunes.
2. And then hold the Home button and Power button at the same time for 10 seconds.
3. After 10 seconds, release the Power button. Do not release Home button, keep holding the Home button another 10+ seconds. You will see a message in iTunes that it has detected an iPhone in recovery mode.
4. Your iPhone is in DFU mode now. Click OK and click Restore button in iTunes.

here is also a link to a video of some one doing this:
http://www.youtube.com/watch?v=-KmHNSE3CZI&feature=player_embedded

hope you backed up =) n hope this helps

put it on DFU mode. then, try to restore it using iTunes.

I believe that you have a problem w/the home button. maybe it's pressed all the time, so the phone cannot boot.

try dismatling the screen again, and check the home button contacts.

if you think the contacts are not ok, try to replace the home button.

if yo thinks there's no problem with the home buttons, try to enter to DFU mode:

1. turn off and connect the iphone to the USB.
2. press and hold power button for 5 sec
3. press and hold power and home button for 10 sec
4. leave the home button pressed until the computer recognize the iphone as a DFU device.
5. restore with iTunes.


Cheers,
Gery

if you don

To getout from stuck or in DFU mode try this.......To Normal Mode Just Keep Press Home+Power For 5 sec Then
Release The Home Button And Keep Press Power Button for 50 Sec U Phone Will Powering On
Regards..
If your iphone is still in stuck after trying the above instruction you must jailbreak it and unlock.then enjoy using your iphone.If you want some help heres my YM:[email protected]

try respring it (central + power buttons together and then connect to iTunes in safe mode,choose full restore (it will erase everything but if you have back up can be restored).

Try restoring in DFU mode, which is different than recovery mode. I happened to stumble across it while trying to restore an iPhone 3G that a user unplugged in the middle of the 3.1 update. It kept showing an error of 1611 or 13 and wouldn't restore in recovery mode. I found this DFU mode option and the restore worked fine. The DFU mode keeps the iPhone OS from loading, so you don't run into as many compatibility problems. Go into DFU mode, then try restoring the phone and see if that works.
http://techierambles.blogspot.com/2009/09/restore-iphone-with-error-13-or-1611-in.html
To enter DFU mode:
1. Connect your iPhone to your computer
2 . Turn iPhone off. You may have to hold the power and home buttons down together to force the phone off
3. Once the phone is off, hold the power and home buttons together for 10 seconds exactly
4. After 10 seconds, release the power button but keep holding home until the computer recognizes that a USB device was plugged in
5. iTunes should detect your iPhone correctly, and also allow you to restore to the factory default settings