put away a working p855-s5312 about six months ago. Now when I turn on the power button the power light stays on for about 5 seconds and goes off. The battery is charged and I have tried 2 power supplies. remove the hard drive, reseated the memory. Also tried a cold shutdown (remove the power supply and battery and hold the power button down for 30 seconds). This thing was working perfectly when I put it the shelf.