New build, on booting restarts on its own only ONCE!

[kygregkim]

Hi,

I have 2 brand new builds, one has ASUS TUF Z390M-PRO Gaming other with ASUS Prime Z390-P.
both with i5-9600K power Corsair 750w
first build with CX750M,
latter TX750M
Same ASUS RTX2070 Turbo 16GB Ram etc

The oddest thing is when I turn the PSU Switch on, the first cold boot would always boot for 2~3 sec then everything shuts down like if it was restarting and then it boots fine. Any warm or cold boot after that is completely fine, no hurdle, just straight boot to windows.

However, after turning the pc off, I switched the PSU off and on again and I will have the same issue, it starts for 2~3 sec then restarts on its own and this problem will not repeat again until I turn the PSU off.

I first thought it was my powerstrip issue so I plug it on a different wall with no strip, same issue, only once.

Right now, both computer runs fine, windows installed, 10+hr Prime95 no problem, furmark whatever but switch PSU off and on, it will have that booting issue.

is this some PSU safety feature that I never knew? why is this happening to both different power supply?

 

[Onus]

This is often a symptom of a CMOS / BIOS issue; possibly a low battery or more likely some kind of mismatch. Although these were new, it is possible the CMOS batteries on them are low. You may also need to clear the CMOS on them and then manually make sure they show the correct settings for the system, particularly the RAM.

 

[MeanMachine41]

I agree with Onus in so much as it probably is CMOS / Bios issue. There are some Bios bugs that don't retain RAM settings on a cold boot that have mostly been rectified with a Bios update.
That restart during post cycle is your Bios setting your RAM for best most suitable/stable timings and voltage and will retain and boot with those timings and voltage until your next reboot.

 

[ron2456]

I had a similar issue with a Asus Prime B350, where the system would boot twice. Turned out the entire prime B350 range of motherboards had that issue.

 

[kygregkim]

I had a similar issue with a Asus Prime B350, where the system would boot twice. Turned out the entire prime B350 range of motherboards had that issue.

it seems like TUF in my example seems to have it too unfortunately

 

[kygregkim]

This is the most bizarre thing I have come across with motherboard, someone posted on ASUS forum about the double boot and moderator says they are made to do so, they intentionally recalibrate everytime PSU is turned off.

https://rog.asus.com/forum/showthread.php?49368-pc-boots-twice-and-3rd-time-boots-normally-to-windows-(-only-happens-cold-boot)