iPhone 3G will not charge/turn on properly. Please help!

[Isabella Charlotte]

For some reason my iPhone 3g is stuck on the screen where there is a battery with minimal level, with a lightning bolt symbol underneath it.

http://i51.tinypic.com/xdczrs.png

It won't charge on the wall charger nor the computer, its been stuck on that screen all day.
It is unlocked/jailbroken, so I'm trying to do anything BUT restore it, because I don't want it to lock back up again.
Plus, I don't want all of my things to erase.
please help me, I need this fixed fast!

 

[Europa]

You don't back it up in iTunes? If you do, you just apply the backup after restoring. You could try a hard reset, but you'll probably have to restore it if that doesn't work. Press the home and power buttons for about 10 seconds. If it doesn't boot, you can shift + restore it without locking it by using a jailbreak tool to create a custom firmware with a preserved baseband.

 

[fijiman]

Are you using the same USB charging cable on the computer and wall charger...? if yes try a different cable...make sure the bottom charging port on your iPhone is clear of any "fluff" in the corners....my old 2G suffered terrible charging problems due to this....I use a pin to clean out, deep in the corners