Hey Everyone! I'm new to Mac's and new to this board. I've been ransacking the interwebs to find an answer to this problem. No dice. Took it to an AASP and practically got a shoulder shrug. Here's the rundown: Mid 2009 15" MBP5,4 2.53Ghz Core 2 Duo OSX 10.9.3 Bought used. Seems I'm at least the 4th owner. Bought with dead battery. Previous owner used it exclusively plugged in for a year, maybe 2. Machine shows no battery installed. Replaced battery. No change. Performed SMC until I was blue in the face. No change. Took to AASP, diag won't see old battery or new battery. AASP even had known good battery to test and also would not see it. I've torn the machine down completely and inspected the logic board for any obvious signs of failure. Looks fine to the eye. I've ordered a replacement Magsafe port just because it's relatively inexpensive and I've got nothing else to try. Even the AASP asked me if I'd let him know what I find because it was not something he'd seen before. So... any thoughts?