Hi all, until yesterday my iPhone 3gs was working perfectly, I had no problems but in the morning just did not want to be charged via USB and windows 7 will not recognize it.

I do not know why if anyone had a similar situation and solved the problem please tell me more about it.

Thanks

Likely ESD to the dock connector (or a damaged USB cable)
This is a hardware issue

When i connect USB to the wall charger it works perfectly but in the PC it doesnt work.

Originally Posted by lahaine

When i connect USB to the wall charger it works perfectly but in the PC it doesnt work.

This could be either a problem in the phone (the dock connector board) or with the PC's USB port or even with the USB drivers or even your BIOS. However if it has occurred suddenly, then it's likely the problem is in the phone.

Basically, like all USB devices there is a negotiation process between the device and computer before the computer starts supplying power over the USB cable.
When connected to the wall charger, this negotiation is skipped and as long as the phone detects the correct resistance on certian pins in the dock connector, it will accept the current from the charger.

It could be a problem with the chip in the phone that handles this negotiation.

You say that a must go to the service ?

Yeah, I have heard a lot about this problem. Apple should sort it out as soon as possible