I disabled Compatibility Support Module (CSM) in my ASRock motherboard's BIOS because a Fortnite tournament required Secure Boot. After restarting, the computer boots directly to the Windows login screen, and the ASRock startup screen no longer appears, so I can't press the BIOS key. I also tried entering UEFI firmware settings through Windows and reset the CMOS by removing the battery, but the display remains black whenever I try to access the firmware. I'm using a Sapphire RX 580, and neither its HDMI nor DisplayPort output shows the BIOS screen. How can I regain access to the BIOS and enable Secure Boot?
3 Answers
Perform the CMOS reset exactly as described in the motherboard manual: shut down, switch off and unplug the power supply, remove the battery or use the clear-CMOS pins, then hold the power button briefly before reinstalling the battery. Make sure the monitor is connected to the output that becomes active after the reset. If clearing CMOS still does not restore the startup screen, the board may need a BIOS recovery or a temporary different GPU to regain video output.
Try reaching the firmware through Windows: hold Shift while selecting Restart, then choose Troubleshoot, Advanced options, UEFI Firmware Settings, and Restart. If the screen goes black at that point, the system may be entering BIOS but the graphics card is not displaying the firmware image.
The most likely cause is the graphics card’s firmware not supporting the display mode used when CSM is disabled. The RX 580 needs a UEFI-compatible GOP firmware to show the BIOS screen in pure UEFI mode. Connect the monitor directly to the graphics card, try every available output and a different cable or monitor, and check whether your motherboard has integrated graphics you can use temporarily. If possible, install another known-compatible graphics card to enter BIOS. A card vBIOS update may help, but only use the exact firmware and flashing procedure provided for that specific Sapphire model; do not flash a generic RX 580 BIOS.
I tried that route, but the display stays black instead of showing the firmware screen.