Strange but interesting, Did you get a beep and/or light code?
If you got them, count the times it beeps and/or the light blinks, It will be either in Morse Code (example of morse: short blink (.) long blink (-)) OR a diagnostic code like beeping 6 times like mine does. And this problem seems to be similar to me, I had a problem with the P7-1423w before and your having the same problem, try cracking open your PC, and remove the graphics card if you can, No graphics card? try replacing your Lithium battery like mine needed after 3 years. If you have a 3-volt lithium battery, and had it in there for 3 years, it might be the time to replace it.