Question system won’t boot after new cpu?

[n0rthV]

okay, so i’ve ordered a new cpu the ryzen 7 5800x3d.
i wanted to change my old ryzen 7 2700x.
also ordered new case, so i just moved all parts to the new one.
problem is, now my system won’t boot at all..
after i was done, first thing i noticed that the yellow led (dram problem (from manual) then after that the red led (cpu problem ( also manual) lights up.
both for approximately 1-2 seconds.
the computer boots up, shows the uefi dialog and then either gets stuck in it (if i press f2 in time or del it opens the bios) or the windows logo pops up in an infinite loading screen.
it is hardcore weird because i get a different situation all the time.
first thing was the recognition of the new cpu (press f1 for SETUP), then it started bios (also noticed my 3200Mhz Ram was down to 2400), press F10 to load, it restarts and then either the windows logo or infinite uefi options, but after the 3 seconds for the f2 or del action you can’t do anything.
i believe it’s the motherboards fault, but before i go and buy a new one i wanted to ask what i could do to make it work maybe.

tried:
removing cmos
checking all power connections
looking at the cpu socket for thermal paste or dust (nothing there, cleaned it, same thing)
using old cpu, same problem
updating bios to the newest version with ez flash 3
using only one DIMM Slot
boot override with the nvme ssd (system partition)

setup:
Asus b450-f gaming
amd ryzen 7 5800x3d new
7 2700x old
gigabyte rx 5700 xt
2 nvme m.2 1tb/512gb
1 ssd 250gb
1hdd 1tb
2x16gb kingston fury 3200mhz
bequiet straight power 11 850w
be quiet dark rock pro 4 250w tdp

 

[COLGeek]

Sounds like you may have a short. Like something sticking into the back panel or an extra stand-off/mounting point under the motherboard.

 

[n0rthV]

Sounds like you may have a short. Like something sticking into the back panel or an extra stand-off/mounting point under the motherboard.

nope, just uninstalled from the pc case and tested if the case was causing this problem (short maybe??) but it doesn’t.
i just got a new mobo b550-f gaming.
same problem..
first orange light (dram) then red light (cpu) then white (vga)
the vga light stays steady when booting, but before im not getting the orange and red light away i’m not bothering booting.
it will just be stuck again

 

[SkyNetRising]

Set dram voltage to 1.35V.

 

[n0rthV]

Set dram voltage to 1.35V.

didn’t change.

installed the mobo back into the case, it recognised the new cpu, asked if tpm was active (chose Y bc it is not), the mobo leds light up one after another, then the boot light turns on, windows logo comes up, loads a little and then it’s just black screen.

 

[n0rthV]

now it doesn’t even recognise boot drives/any drives