So I have this new computer, not brand new but new to me. Dont know the exact model number but its a HP which originally came with vista, it has 6 gb of ram, phenom II X4, and i have added my own video card, the video card is very low power, doesnt require any extra power from the ps. The computer has been working just fine since i got it a few weeks ago. I was on it last night, shut everything down just fine. I pressed the power button this morning, nothing as much as a flicker occurred. Oddly enough, the last few days when the computer went into sleep mode, and I woke it up, no video would pop up, fans would spin and stuff though, and I would have to manually shut it down and restart it, and when it would start back up, it acted like it was in hibernation. Lately, the draw of electricity from christmas lights has flipped a few breakers. However, i checked and they were all fine. Other things to mention is the fact is that there is no light on my mobo to check, however, the power supply has a light built in, which does light up normally when plugged in. I did a power supply test with a paper clip to discover it would turn on just fine. The last thing is that when I move it about, such as leave it UNPLUGGED for a few minutes, it requires a few minutes to charge up before I can turn it on. So my best guesses are that possibly the power supply isnt giving enough power now? A visual inspection of all the parts yielded that I could not see any physical damage, no blow capacitors or anything. I really need this figured out, so if I could receive help I would appreciate it.
I think that is a problem in PS. I also had the same problem. Try this method : remove all cables of power supply and short black and green wires (normally 15 and 16 pins) using paper clip. short the pins for some time until power supply turn on. then keep it on for some time and connect all cables and power cords immediately. then turn on your PC. It will start your PC but you have to do this each time when you start your computer. So you have to change your PS.