I was on vacation for a week and during that time I had unplugged my pc from the socket in the wall, so it was completely without connection to power. I got home, plugged in the cord and booted the machine. It ran, but there was 'No signal' on my monitor so I figured the cable to my monitor had somehow gotten loose, but it was as it should be. Then the pc powered off by itself. I went to press the power button again, but noticed the power button (which usually has a colored light) and the light that indicates if a harddrive is active was blinking on and off. I have never seen this before.
Also, it's impossible to get the pc running at all. As soon as I plug in the power cable in the wall the lights starts blinking and if I press the power button the blinking stops.(Holding it in makes them start again.) Nothing starts spinning, no fans and no harddrives.
In addition, the little green light on the motherboard doesn't light up either. I've noticed though that one case fan spins for half a second, then stops, then spins again for half a second etc. Like it gets short bursts of power.
Does it sound the PSU is dead? Or could it be a fried motherboard or CPU? Everything is only a year old. I'm leaning towards a PSU issue, but I want to hear someone else's opinion before rushing out and buying a new one.
There are two lights on the front of your case, one is for the power and one is for the harddrive. The power light, unless hooked up wrong, will not show HDD activity. Usually if the power light is blinking, the computer is in suspend or sleep mode. Try disconnecting the power cable and resetting the bios.
If you want to make sure the PSU is working, you can short out the two pins on the atx connector and see if it comes on. Before you do though, disconnect everything from the psu first incase something goes wrong.
With the psu UNPLUGGED, use a wire and short the green (power on) wire to any of the black (ground) pins. Now plug in your psu and flip the switch. If it come on, great. You could also hook up a fan to one of the 4 pin molex connectors to test it as well.
I then tried shorting out the PSU using this guide (to be sure I did it right): http://www.dvhardware.net/modules.php?name=Sections&sop... but nothing happened. I guess the PSU is dead. Although it must produce some power otherwise the power button couldn't be flashing? (I had nothing attached to the PSU when shorting it out though.)