https://forum.asrock.com/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Sun, 19 Apr 2026 06:04:10 +0000 Thu, 12 Aug 2021 01:16:10 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.04 360 https://forum.asrock.com/RSS_post_feed.asp?TID=19386 https://forum.asrock.com/forum_images/web_wiz_forums_black.png https://forum.asrock.com/ https://forum.asrock.com/forum_posts.asp?TID=19386&PID=89685&title=4x4-4800u-bios-error-b4-with-usb-hub#89685 Author: Mike4800U
Subject: 19386
Posted: 12 Aug 2021 at 1:16am

Hello,

I purchased an Asrock 4x4 4800U barebone some days ago. It is
now equipped with 64 GB RAM. It works fine with Ubuntu 20.04.

To save USB ports and more simply share keyboard and mouse
with another computer, I tried to use the USB hub in the monitor
(HP w2558hc). When I plugged in the hub, the keyboard and mouse,
all is ok.

When rebooting, the BIOS now stops with B4 error. It is not
possible to enter the BIOS setup anymore. To boot, I have to
plug off the USB cable and plug it in when the Linux boot is in
progress (or later on). Afterwards all is ok again.

The same happens, when the USB printer or a USB stick is attached.

The boot process works well, when I plugged in only keyboard and
mouse directly. It fails in other cases.

The printer is working fine, so I don't think its a problem of
the printer or the USB hardware of the 4800U. Same with the
monitor USB hub.

The BIOS is UEFI P1.30 of 11/27/2020 10:18:42.

What can I check to isolate the problem?

Best regards
Mike4800U]]> Thu, 12 Aug 2021 01:16:10 +0000 https://forum.asrock.com/forum_posts.asp?TID=19386&PID=89685&title=4x4-4800u-bios-error-b4-with-usb-hub#89685