Can't enter DFU mode while connected to computer

[sekin67835]

Hey guys, a quick question.

I can't enter DFU mode when it is connected to the computer.

But when i unplug it, i can enter DFU mode, however right when i connect it to my computer it starts up the phone.

Any ideas on how to fix it?

[dinobotterrorize]

I don't know where else to post this so instead of starting another thread I'll jump on this one. I almost have the same problem.

Same problem. It took me forever to find a thread that was recent AND had the same problem as me. I have a jailbroken (via jailbreakme.com) iPhone 3GS on 4.0.1 firmware (I'm pretty sure it's on a firmware that's not to far from the release of iOS4). iTunes is up-to-date and so are the drivers for my USB/firewire hub on my computer.

My situation in the steps they happened:
1. My iPhone didn't load/charge/play music in my car when it was connected via USB.
2. Battery drains to about 4%. I tried connecting it to my computer, my brother's computer and his wall charger. I even tried a firewire charger from my 4th gen iPod. Tried using a respring app to restart my phone. I even shut it off via holding the sleep/wake button until the red slider showed.
3. Went to hard reset the phone. It turned off and stayed blank. I connected it to my computer via USB and it stays blank. Blank like the screen doesn't even turn on. Because when it does you can see the color black(when in a well lit environment) and it emits a light when you're in a dark place(when in a dark environment). When I press the sleep button to turn it on, the phone shows the dead battery screen with the "you need to charge it" icons below the battery.
4. Switched to the firewire cable and tried turning it on. This time it only shows the dead battery icon. I don't see the plug > lightning bolt icon.
5. During my second hard reset/DFU mode attempt (still connected via firewire) the dead battery screen shows, blinks red, and before I can count to ten (I got to 7), it flashes white and shuts the screen down. I continue to counting to 10. Release the sleep/wake button and before I can count to 10 again (I only got to 3 this time) the dead battery screen (without the white icons underneath) comes up again. After blinking red it shuts the screen off.
6. Continued to hold down the home button to no avail.

My diagnosis: The dock connector or motherboard is pooped-up.

My possible solution: I need to take it apart and replace the dock connector or change the battery.

Other thoughts: I've tried restarting my computer while the iPhone was plugged, having iTunes on and off while trying to reset/recover/DFU and leaving it connected to try and charge it. I'm 21 months into my two-year contract with AT&T. I'm sure I have no warranty time left.

What do you guys think? Did I hit the nail on the head? Is there a way to fix this WITHOUT opening it(via software I guess)?

[sekin67835]

For you, i think you have a dead battery. Did you try a wall outlet by any chance?

For me, i can't even enter DFU while it's connected to the computer.

[sekin67835]

bump,

Tried various computers. Still won't work. Any other way to enter DFU?

I tried 10 seconds, 9 seconds, 8,,7 ,6 ,5 etc. None that works.