iphone 3g not being detected by pc
treid windows base pc / apple mac's
tried different usb port and cables
no sound nothing in device manager
goes in dfu mode i can see itunes picture on iphone 3g screen but if its plugged, pc wont detect at all
i have replaced battery
i have replaced data port
if phone is off and if i plug into pc iphone comes on with apple logo but pc doesnt detect at all
before this problem i jail breaked it was working then i replced iphone housing after that it stoped detected and charging
tried mains charger but doesnt charge ,may be its taking some charge but doesnt show on screen

please help, dont know what happend i did everything tried so many videos from you tube, does anyone knows what it could be, i can pay from paypal