First of all i bought the computer from a retailer. This problem occurred within this week. Sometimes before I have had some unexpected shutdowns but they were rare. I decided to buy a small fan to cool the system.
Now when I press the turn on button, the lights open and there is one beep and it shuts down immediately. The screen does not open. When I press it for the second time it boots normally without showing any safe mode messages for failing to boot. If I restart the computer such problem does not happen.
And today when I tried to turn it on, it turned off for the first time as usual and then it took like 10 seconds when I pressed the button to turn on.
I'm not sure what the problem could be. The power adapter, I used a new one and it still happens. Although the adapter is a cheap one, it could still be accused, maybe. The computer makes no noise at all. I have never opened my computer to clean it, I don't know how to do it but could it be dust at the motherboard/CPU/CMOS? I'm just worried if it's due to a bad CPU or motherboard.