While you are waiting for help >
ASRock B5550M Pro4 Manual > https://download.asrock.com/Manual/B550M Pro4.pdf
Edit from moderator: The PDF was the Japanese version. Switched link to the English version.
ASRock B5550M Pro4 Manual > https://download.asrock.com/Manual/B550M Pro4.pdf
Edit from moderator: The PDF was the Japanese version. Switched link to the English version.