Acer aspire l320 problem

Hello,
MY COMPUTER when switched on will not respond, mouse will not work , screen will not light up as normal just a window saying no signal

Do the fans spin? If not, it could be a bad power supply.

Hi, I read this topic and i happen to have the same exact computer, And the same exact problem. Here is all the details i can think to add. I was using my computer as per normal using a drawing program so i wasn't doing anything heavy.It suddenly froze completely so i restarted it.It reached a loading screen when i restarted it and it froze.So i once agan restarted to my mouse,keyboard and monitor not responding.I kept trying to turn it on or off to see if it was just some small glitch or whatever. It didn't work untill randomly an hour later i tried again with everything but my monitor plugged in [all i had plugged it-power cord usb mouse usb keyboard and a usb wireless internet stick] the computer worked better than ever untill i left the pc on overnight and i went to turn the monitor back on,moved the mouse a little,It was laggy then it froze just like before,I restarted to find the same problem. my mouse, keyboard and monitor get no power BUT my monitor does recognize that it is plugged in because it goes to an idle black screen with a flashing light as if it is hooked in but just my pc is off.When i started my computer it sounds asthough it is starting up correctly and the fans spin as good as ever,just want to add that when i unplug my mouse and replug it back in i get a very brief flash of the mouse lighting up [it's a usb infared mouse so it shines red] i have also made sure the inside is dust free but it's kinda hard to clean as how small the box is and half of it is covered by metal that i cannot figure out how or if it is removeable,i have basically no experience with computers in this way as i am only 16 and have only had a computer for a few years.