Overclocking F3-14900CL8D-8GBXM

[julianbos]

15 is pre-memory north bridge initialization. That is memory related but can also be improper system voltages. If it were the memory timings or Vdimm itself, you'd get 55 most of the time. So i guess its time to manually adjust VCCSA, IO(a) and IO(d)? Start with small offsets, maybe

VCCSA +0.036V / +0.060V
IO(a) +0.015V / +0.036V
IO(d) +0.015V / +0.036V

See if that changes things. Also keep a higher tRFC until your can consistently POST and have stable settings. You can try to lower it later on.

Still no success..
I recorded the led codes, both normal boot and the 2400mhz memory profile boot.
Then I played the video in slowmotion in order to note the led codes properly.

Normal boot: Ab-reboot-9-19-15-16-3b-4F-60-62-69-68-71-79-9A-98-96-9C-64-b2-24-89-99-88-A2-Ad-AE-A0-04-A0 (Windows).

2400mhz profile: Ab-reboot (takes a long time and the gear button lits up for a nanosecond (The Gear button changes the base clock stepping from 0.1 MHz to 1 MHz intervals)) -8-19-15-reboot (takes a long time and the gear button lits up for a nanosecond) -8-19-15-36-3b-92-4F-60-61-68-69-71-79-9A-96-9C-b2-24-99-A2-A9-Ab (Bios screen which asks to load optimized defaults).

Hope this helps