Windows 7: Aspire M7720 blinks power once, not turning on

I have a Aspire M7720 using for 5 years and no hardware changes. I usually turn on my computer and leave it overnight. I have an additional USB fan plugged in.

I was using the computer just now when suddenly it turned off by itself. I waited for 5 minutes (because my computer will fail to startup during Windows logon screen and stuck). After 5 minutes, I tried to on it and nothing happens. So I switched off the power supply and waited for another 5 minutes and on again. This time, the power light (cylinder thingy) blink once and nothing happens.

My LAN cable was plugged in and flashing all the time, so I supposed it is working.
My USB fan was also working when the computer was switched off and power supply was on.

I could not know what problems do I have, but I knew the AC Plug was working.
Can it be the motherboard? Hope I gave enough details. Thank you.

What were you doing while it turned off?

Using another PC. You mean when the power supply turned off?

I mean when the computer turned off by itself, what were you doing with that PC? Playing a game? Watching a movie or what?

I was playing a game.

Unplug the PC from the wall, hold the power buttonin for 20 seconds, then reconnect it and try to start it.

If this fails try another power supply. A local shop may allow you to hook theirs up to see if that is the problem, then you can buy the PSU there or online.

Power Supply Calculator

Hello Index,

Exact same thing happened to one of my old systems as well, I was doing some CPU intensive task. I took it to a technician, they could not figure out what was fried. Ultimately had to replace the mobo.

You must take it to a technician to get it checked.

I’d suggest to try for power supply issue first, if its not working get it to a techie.

Thanks everyone for the replies. Just found out from the technician that the power supply inside the computer is broken.
Already sent my PC to the technician. Thank you!