I have an Acer e1-531. It was working smoothly with a win7. I decided to upgrade CPU and bought a core-i7 CPU and installed successfully.
I started the system, everything worked fine. Then after exactly 30 minutes, the system shuts down without any message, it just shuts down instantly.
I tried to boot system from a USB ubuntu 14.04 but it was exactly the same, system shuts down after exactly 30 minutes.
I contacted the dealer (I bought it from Aliexpress) they told me it is the Bios and I need to upgrade it. Then I upgraded Bios to the latest version using company's website utility. It happens exactly the same.
I have tried many thermal monitoring and CPU burner tools without any sign of error or problem. I even pushed the system to its limits, where temperature reached to 100 c but nothing happened, system just worked normally until it reached its 30 minutes, then it shut down again (while CPU temperature was 46 c)
To me, it seems some kind of setting / configuration problem rather than fault or issue. Because if it was a fault or error it could not happen exactly the same time in all conditions, the time period would change. I imagined may be I have changed some kind of hardware configuration, cable misplacement when replacing CPU, but I do not know of any.
I appreciate if anyone have faced similar problem before or anyone knows any hardware setting on mother board that can cause or start a shutdown timer, let me know.