Hey guys,
 
Since winter and temperatures dropped i'm having a "cold boot" bug situation.
 
When i start my PC in the morning on the first boot my screen stays black, no uefi/bios screen displayed. Motherboard LED displays shows "3B" which translates to "Post-Memory South Bridge initialization is started" according to the MB manual and 2 red leds are lighted:
 
 - PCIe LED for PCI-E 2. According to MB manual: "The LED will remain on when this PCIe slot detects an initialization failure in PCI-E 2."
 - PCIe LED for PCI-E 4. According to MB manual: "The LED will remain on when this PCIe slot detects an initialization failure in PCI-E 4."
 
In my PCIE 2 port my graphic card is plugged, in the PCI-E 4 there is nothing.
 
BUT! If i just let the computer like this for like 1 min, turn it off then back again the PC boots normally. If i then turn the PC off or just reboot it, it works perfectly. It only has this problem after staying off for a long time when i go to sleep. Dunno if cold temperatures in the morning play a role in this or not, but it seems it started to do this since winter came and temperatures dropped.
 
I didn't change anything before this happend, my CPU is a 9900k which i have put back to stock settings in case o/c was the problem but it didn't solve the problem. Also MB is running the latest bios.
 
Any idea?
 
Thanks in advance for your help :)

 
Since no one is answering, and those peculiar malfunctions led me to ruminate a bit, I offer the following five
lunatic theories in descending order of madness :|
 
1. Mooninites are reprogramming your CPU while you sleep .
2. The cold, then hot is causing your MB to flex slightly, and has made one of your cards work loose in its slot .
3. The cold computer, then warm air when you get up causes a little condensation on the circuit boards and pins .
    Just enough to make tiny shorts, and unwanted grounds .  Once it dries out it's back to normal .
4. You have a delaminating circuit board, or capacitor .  Once warm the delamination closes and it's back to normal .
    If that's the case, then the component will continue to degrade, and ultimately fail :(
5. You have a weak CMOS battery, and the cold stops it from working altogether, goofing up the BIOS .
 
... as seen from Mons Ampère
 

 
Dear Mr. spider;
If you can reach your BIOS switch while the computer is running:
try the "hot flash method" https://www.evga.com/support/faq/FAQdetails.aspx?faqid=59733 to fix your BIOS 1 .
It worked for me, and I have the same board you do .
 
To the Moon ..
 

Neutro
Long update after: the problem was coming from my RAM. Strangely it worked without any problems for a long time using XMP until finally it didnt.
 
I removed XMP, setup the RAM manually and no more problems.

Good troubleshooting.