If the keyboard was plugged in when it got "thrown", the MoBo may be cracked or the ADB port's connections may have been cracked. Open the case back up and visual the MoBo around the ADB port with a reading glass for cracks. If you find any, try to solder a wire across the traces to fix it. Scrape (towards the break) the green varnish off the copper trace, tin the copper with solder, lay a tinned piece of wire over the crack and "sweat" the connection. (Add heat but no extra solder, very quickly).
If you don't find any cracks, try zapping the PRAM and/or changing the battery. Without the keyboard, you can zap the PRAM by removing the battery and pressing the power button for 3 or 4 seconds with the 6100 unplugged. Let it sit for 20 min and replace the battery.