POST Screen/BIOS Doesn’t Show With DisplayPort

Problem Symptom

With DVI, VGA or HDMI connection to monitor, POST (power on self test) Screen shows up normally and it is able to enter the BIOS Setup; but with DisplayPort connection to monitor, can’t see POST Screen (BOOT Screen), monitor remains blank or black screen until windows logon screen shows.

Possible Cause

This issue doesn’t relate to the DisplayPort cable, instead it may be caused by OS settings or hardware (BIOS or GPU firmware) settings:

1. If you are using a DisplayPort 1.3 or 1.4 monitor, and the graphics card (GPU) is from NVIDIA; the graphics card needs a firmware update;

2. The Windows and/or BIOS current boot mode is Legacy, not UEFI;

3. The computer’s on-board graphics card has priority over PCIe graphics card, while the monitor is connected to PCIe graphics card

Solution Steps

We suggest that you follow the steps one by one; and you don’t need to try all the steps below, if it works at some steps, you may skip to the last step:

1. Use temporarily another monitor connection (such as DVI or HDMI etc.) that can show POST Screen so as to try the steps;

2. If the graphics card is from NVIDIA, please check this link below and download the tool to update the firmware:

https://www.nvidia.com/object/nv-uefi-update-x64.html

3. Check if your Windows is able to boot with UEFI

Run “msinfo32.exe” (System Information) and check the line ‘BIOS Mode’.

1) If it is already ‘UEFI’ (like the above screenshot), go to next step and continue;

2) If it is Legacy instead of UEFI, you need to convert it.

Follow either the instructions:

https://social.technet.microsoft.com/wiki/contents/articles/14286.converting-windows-bios-installation-to-uefi.aspx

or,

https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10

4. Check if your computer’s BIOS is set to boot with UEFI

1) Enter into BIOS Setup;

2) Find the option “CSM (Compatibility Support Module)” and set it to “Disabled”;

set it to “Auto” may works in some cases while sometimes not.

The option “CSM (Compatibility Support Module)” is usually under ‘Boot’ menu or under ‘Startup’ menu in BIOS Setup.

3) NOTE that once CSM is ‘Disabled’, you can’t boot an operating system that is not UEFI compliant; so if you have several operating systems, make sure all of them have been converted for UEFI.

5. If your computer has both on-board and PCIe graphics cards and monitor is connected to the PCIe one, change the priority (in BIOS) to PCIe graphics card, or disable the on-board one.

Follow the instructions:
https://smallbusiness.chron.com/disable-onboard-graphics-card-bios-53738.html

6. Try to switch graphics card from PCIe 2.0 to 3.0 (if the motherboard allows you to do this).

7. Reconnect you DisplayPort cable and monitor, then reboot, and you should be able to see the POST screen / BIOS.