ipone wont connect to any computer

[c_a_loper]

Ok here we go I will describe what im experiencing as best as I can

I bought an I phone 2g from ebay, auction stated iphone no longer charged, simple fix.

got the phone sure as S*&^ it wouldnt, unless, I connected it to my ipod connector in my truck, the one that connects to the back of the stereo directly, not an fm trans/ cig charger. The phone came to life, but would not charge, it thought it was but after unplugging it just died, messed around in the settings turned everything off and let it sit for a few hours. came back to it pulled it off the charger and died. So i did the restore from the settings menu, wiped everything start from scratch. I was gonna do it anyway so I hoped that would fix the hiccup with charging. I let it format and charge overnight.

Now the phone has a full charge and stays onn when off the charger, the phone is telling me to connect to itunes to restore, here inlies the problem. No computer will recognize the iPhone. steps i have tried, recovery mode and dfu mode, iphone will not enter these modes, does it need to recognize it is connected to the computer to enter these modes? I have tried both numerous times it just resets shows the apple logo and returnes to the connect to itunes screen.

I have tried to verify the usbaapl.sys file is there and amd services are running, on my xp laptop everything is good, although the usb might be a 1.0 version, on my new hp I have vista 64, i cannot find the sys files anywhere. I have uninstalled and reinstalled itunes, even tried version 8.1 still no luck. Also tried plugging into my friends mac, no luck, I dont know anything about macs so I didnt go poking around.

I also have a brand new usb dock data cable, not just a charge cable.

Now question for all that are smarter than me, how do I test if there is something wrong with the logic board or anything interior? Any ideas, please dont say try entering dfu or recovery mode, the iPhone will NOT do it, or are there other ways of doing it without the press and hold... release... 10 sec blah blah.

Should I just send it in to an online place that does free inspections? if so do you have recommendations?

thanks to all

[iNinja]

I dont know if you have tried this particular method, but this method puts the phone into "restore" mode, not DFU mode.

Turn the phone off
Plug into pc - with itunes running
Hold down the home button and do not let go
Turn the phone on (whilst still holding the home button)
Itunes should state that it has found an Iphone in restore mode, and it needs to be restored and synced. If this doesnt happen you iPhone is likely, for want of a better word, to be screwed

[c_a_loper]

yup tried that too, i read somewhere it might be my flex cable...