I just built my first PC and it initially powered on normally. I entered the BIOS, but it did not detect my boot drive, so I opened the advanced settings and enabled CSM. After saving with F10 and pressing F8, the display went blank. I restarted using the power button, then tried entering the BIOS again. The fans briefly sped up, a small motherboard LED flashed through three colors, and then the fans slowed down, but I still get no image. The boot device is a USB flash drive. What should I try next?
3 Answers
Start by clearing the CMOS to restore the motherboard's default BIOS settings. Turn off the PC, switch off and unplug the power supply, then use the motherboard's clear-CMOS button or jumper as described in the manual. If neither is available, remove the coin-cell battery for several minutes, reinstall it, and power the system back on.
For Windows 10 or 11, CSM normally needs to stay disabled because modern systems use UEFI. After resetting the settings, leave CSM off and make sure the USB drive is connected properly and appears in the boot-device list. You may need to select the USB's UEFI entry specifically.
If clearing the CMOS does not bring the display back, check the USB connection and reseat the drive. Also verify the monitor cable is connected to the correct graphics output, then inspect the motherboard's diagnostic LEDs during startup. The flashing colors may indicate the stage where POST is stopping, so the board manual should explain what each light means.
I'll check the manual for the clear-CMOS procedure and reset the BIOS before trying anything else.