Sometimes it just power off and on again without loading anything.
Sometimes can load bios. But most of the time just hanged.
I suspected now it's mobo. Cause after load windows sometimes I see 16gb ram, sometimes 8gb ram.
Please advice if I need to purchase back same model MOBO?
Thank you
When you power on the pc, do go to BIOS via F12 to BIOS and no need F2 BIOS setting.
In this way you can see the basic BIOS on RAM, HDD, Date/Time, etc; for any discrepancy.
May need to monitor in this way to check for any errors upon booting.
The other issue could be the main power outlet where the PSU is connected to.
As in case sometimes it may surge or spike whereby causing the PSU to cut-off and hence the computer shut-down &or reboot.
Finally you may have to do some housekeeping on the computer.
Maintenance a computer is a need and may have to do it once a while when the system is getting old.
Remove Dust, polish the RAM and internal cards, reseat RAM, Cards, PSU, etc.
Not forgetting the power contacts on the MB and other cards &or HDD/SDD, etc.
If you are doing all these, maybe it time to replace the button battery.
In this way, it is as good as new in giving the MB & System a new lease of life.