No post after CPU upgrade

[eliott]

Hi 

I've upgraded my ryzen 5 2600 to a ryzen 7 5700x on my Asus prime b450 mkii but now it has no post.

It says ryzen 5000 series compatible and it says online that the cpu is compatible with the motherboard...

What should my next move be ? 

Update the bios using flash back or reinstall the other cpu to update the bios ?

CMOS reset maybe I had my ram at 3200 MHz maybe it's causing instability

Unfortunately my motherboard doesn't have boot sequence LEDs but all lighting turns on as normal

Thanks for your advice 

[Pixelfie]

Yeah, try updating the BIOS. 5700X launched later than other 5000 series, so if it says 5000 series ready it might still require a new BIOS for the 5700X.

[Heats with Nvidia]

I would try updating the bios via flash back first. Most probably this will solve your problem. If it doesn`t work, install your old CPU and then try to update the bios.

[svmlegacy]

@Pixelfie is correct, you need BIOS version 3211 to support the 5700X. Reinstall the older CPU and update the BIOS.

[TetraSky]

Did... Did you not update the bios before putting that new CPU in? Yes it's compatible... But not out of the box. You need to be on the latest bios.