PC reboot issue

[kelmen]

my pc recently started to have reboot issue, with this pattern:
- the pc will reboot like a hard reboot
- when pc booting up, it take long time even for the bios boot up process kick in

this usually happened when i'm gaming, as this is my gaming pc
but after bootup, it can happen again even if just trying to surf

the recent hardware changes are graphic card (R9 270X) and AVR

anyone has similar experience?
I did the mem diagnostic, no issue.
any futher approach I can do to troubleshoot it?

the pc is almost 2 years old

 

[i7Baby]

This usually happens because the CPU overheates and shuts down but auto restart on failure is still enabled.

Boot into Safe Mode (F8) and disable auto restart on failure. Then check your CPU temps.

 

[kelmen]

replaced by brand new and better parts, new psu, new mobo, new cpu

reinstalling windows

problem come again.
1st few times shutdown, reboot
later shutdown, won't reboot, new psu seems to kick in a bit then stop at all

what i tried:
- disconnect power to gc, using onboard gc
- disconnect 1 of the ssd (existing 2 ssd, 2 hdd)

problem insist

what's been reusing:
- gc
- casing
- monitor
- usb keyboard, usb mouse
- 2 ssd 2 hhd
- dvd combo

apart from electric power issue , which i'm using AVR, old and new one, been keep switching both of them for testing

what can cause power/shutdown issue?

 

[i7Baby]

CPU overheating.

 

[kelmen]

a late update.
2 items replaced, and it is working fine:
- gc (new geforce card)
- psu (using back old/prev psu)