No signal input and now pc wont switch on ?

Hi, First when i switch the pc on, the boot up screen come on windows goes to start and then a light blue windows screen comes on and say its want to check the C drive or some other thing i forget now, it checks the 3 parts and then after that comes up a black screen 'No Signal Input' and the speakers make a pop noise every 20 seconds.

It did that a few times, and now it wont even switch on.

I opened it up and all looks good.


What could this be ?

Thanks,

 

Could be a failed power supply

 

When you said 'it doesn't switch on at all' do you mean the no picture on the monitor, or the computer itself? The 'no signal input' usually denotes the monitor isn't getting a signal from the vid card. A little more info would be helpful as to the type of video card you have, either on-board, AGP, PCI, etc. If it is on-board, then the make and model number of the motherboard and the vid chipset, nVidia or ATI. Also, as MoPar said, it could be a failed PSU.