Оригинальный сообщение: Dan ,
Sadly, it sounds like the logic board has failed something within the CPU logic area. Could be a simple cap issue or the VRM FET’s are messed up. You’ll need to breakout the schematics and board views to trace out the logic or just replace it. But! Given the costs it might be wiser to just get a newer (used) system which supports more than 8 GB of RAM which is the limit in this series.