Windows 7: The Notebook Randomly Turns power off

The Notebook Restarts Randomly

(Tests made on a Windows 7 ultimate clean install)

1-Running on Battery: The Problem doesn't occur

2-Windows (Safe Mode): Plugged in with original charger, the Problem doesn't occur

3-Windows (Selective Startup) Loading only System Services and Plugged in, the Problem occurs

4-Tested without installing video card drivers and the Problem occurs

5-Tested different video card drivers (all WHQL) and the Problem occurs

6-Tested with another Charger and the Problem occurs

7-Tested plugged in to another AC Power socket and the Problem occurs

8-Tested With the Charger plugged in and Batery and the Problem occurs

9-Tested with the Charger plugged and without the batery and the Problem occurs

-Also Run Everest computer diagnostics software: Noticed sometimes a CPU overclocking of 9% then going back to normal. Didn't see any fans information

Dust it out. Take some canned air and dust all intake and exhaust ports on the laptop. Heat is the #1 cause of laptops shutting down at seemingly random times.

But why doesn't it happen while it's running on battery ?

hardware and OS-based power settings may be controlling the amount of power used to run on the battery for as long as possible.

Does it shut off when running on AC with no battery?

Physically remove the battery and run on AC power. If it works, faulting charging circuit on mobo.

Yes it does.

It doesn't work on AC Power without Battery either

I've disassembled the notebook, cleaned the dust off the main ventilator entry. But didn't solve the problem.

If it doesn't work at all, then you still have a faulting charging circuit. At this point you should contact your laptop's manufacturer and seek repair from them.

I have contacted Acer Support a while ago, but no answer.
It's not a matter of working or not working.

Charging circuit fault ? What does it mean ?
Does it mean it doesn't charge the battery ? Because it does charge it.

I Think you haven't read the post.