B4 Error - Help me!

[Mr.David]

Hello!

 

I have an Asrock B450M pro4 with Ryzen 2600, 16 gigs of ram, rx590 and a 240gb a1000 kingston M.2 SSD.

Everything was OK until today when the PC didnt boot. The keyboard and mousepad didnt work. I moved the keyboard and It was good, with Windows + CTRL + Shift i could get to Windows. I updated my BIOS to the latest and done a CMOS restart(unplug the PC, REMOVE the battery and then put a jumper on cmos for 30 sec). 

I have B4 error. What should I do?

[Semper]

ASRock has B4 listed as a USB device error.

Remove all peripherals, and determine if one of them is the cause, add them one by one until the error is reproduced, then check against a different port should you find the error.

[Mr.David]

Solved. After the BIOS update and discard changes in BIOS.