I erased all content and settings on my jailbroken iphone 3g and now its stuck on the start up screen

Formatting an iPhone 3G will erase all the data on your phone, delete all your apps and reset your phone to factory settings. Formatting your phone is a good last resort if you're having software issues with your phone. Keep in mind that the format is permanent and any data irrecoverable.

INSTRUCTIONS:

1.Click the "Settings" icon.

2.Select "General."

3.Scroll to the bottom and select "Reset."

4.Select "Erase All Content and Settings." A warning message will display. Confirm your selection. The iPhone screen will turn off then show a "waiting" sign. After formatting is complete, the Apple logo will display and finally your formatted iPhone will reboot.

Read more: How to Format an iPhone 3G ' eHow.com http://www.ehow.com/how_7640130_format-iphone-3g.html#ixzz1WCkuLtuM

I'm assuming you have a jailbroken iPhone. The reset all button just does not work properly on a jailbroken iPhone. What you have to do now is to plug it in your computer, Run iTunes then hit restore. If the phone can't be detected, enter DFU Mode. Follow instructions here so your pc can detect the iPhone.

http://www.fixya.com/support/r8568726-enter_dfu_mode_iphone_ipod_touch_ipad

If your iPhone is jailbroken, it usually gets stuck.To fix it, make your phone go to DFU mode. Connect your phone to your PC or MAC and open up itunes. iTunes will detect your phone in DFU mode, then simply restore phone by following the instructions given from iTunes.

Put your iPhone to DFU mode and then restore it over iTunes on your computer.
Click here for instructions or use this web address: http://www.fixya.com/support/r4083816-put_iphone_dfu_mode_restore_3_1_2

DFU means Device Firmware Update. If a restore using Recovery Mode doesn't work you will want to use DFU Mode as a last resort. When placing your iPhone into DFU Mode it does not load the OS before attempting the restore


Watch the Video!
For your convenience this tutorial is available in video format also. Click the Watch It button to view the tutorial!








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.


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!

Try to reinstall a jailbroken version of the iPhone OS.
Do not (ever) use reset to factory if you need the device to be jailbroken to function (e.g. in case you are using an officially unsupported operator/plan)

Looks like your iPhone won't boot, It happens sometimes if your phone is jailbroken and you have installed another non-standard language interface, i install Hebrew on my phones, If i then erase all settings it will fail to boot, like yours...
I suggest you restore the phone and re-jailbreak
since you have erased all settings i presume you have no personal data on it, if you do have contacts/calendar/SMS items, try to backup via iTunes before you restore, even when only the apple is showing, sometimes you can connect to the phone via iTunes/WinSCP
Good luck!

How to repair IPhone 3g after Erase all content and settings can i help me thank s

Try doing a factory restore using iTunes or QuickPWN and if you need to jailbreak it again, be careful what apps you download from cydia...some of them cause problems with jailbroken iPhones, just research online for which ones are notorious for problems