Not Charging from wall or PC

I have a 3GS that is having major charging issues. I have replaced the battery and dock, but problem remains.

When connected to power, there is no beep, but charging symbol appears, however, phone doesn't charge.

If connected to PC, it syncs and can restore, but not charge!

If (when) the battery dies, connecting to the charger shows the red battery and the lightining bolt, however, it never charges!

Any suggestions?