Two years ago I bought a Dell Inspiron 1721 (Vista) and it has worked just great! Two weeks ago it suddenly began reporting that it did not recognize the ac adapter/charger (original OEM unit). I ran diagnostics and that is all it would tell me. Checking the BIOS also yeilded a message that the Computer could not "communicate" with the battery (which is WHY it no longer charges). I had the battery tested, as well as the OEM charger/adapter and they are fine. So....I "guessed" and had the DC power jack replaced by a pro. I still have the same problem. I really need the laptop to be "portable" again - It works great on the Adapter/Charger but no longer on the battery. How can I fix this without junking it or completely swapping the Motherboard?