iPhone keeps going into DFU mode
Bought a faulty iPhone 3g 8GB on ebay to play with, switched it on and it went straight to DFU mode so tried to install the FW, this started giving me problems.
In total tried about 30-40 times, in those times it worked about 5 times, so it starts, activates etc etc give it 15-30 mins of use I restart for whatever reason and it goes back to DFU mode.
Opened it up and all looks ok but parts are tiny so couldn't see if anythings broke.
I'd like to fix this somehow, the original owner was quoted £130 from O2 being it was out of manufacturers warranty.
I do have another iPhone to use for parts (not that there's many), his one is used as an iTouch, no phone fucntion
Any suggestions or links to places to ask?