So, since i know how to turn a light switch on, Im clearly the 'expert' and have been stiffed with sorting a Macbook 4.1 with a power issue. Its only working with the charger plugged in and won't charge the battery. Diagnosis steps taken: 1. Charger swapped 2. battery swapped 3. NVRAM & SMC reset 4. visual inspection of magsafe pins. Im assuming since it works when plugged in that the magsafe board is operating ok, so I presume that only leaves a logic board issue? Any other advice/guides on diagnosis....and if it is the logic board, any idea of probable repair cost?