Why does my computer turn on but show a black screen?

Because there is no BIOS logo, Windows has not started yet; this is a firmware, graphics, power, or hardware-initialization problem. Disconnect storage accessories and all USB devices except a wired keyboard. Shut down, remove power, hold the power button for about 15 seconds, reconnect one monitor directly, and try again. If the processor supports integrated graphics, connect the display to the motherboard after removing or disabling the discrete GPU; otherwise reseat the GPU and verify PCIe power connectors. Test one RAM module at a time in the motherboard-recommended slot. Check the board’s diagnostic LEDs or beep code and consult its manual for the indicated component. Reset UEFI settings using the manufacturer’s documented CMOS procedure only after recording custom settings. If a firmware logo appears, continue with Microsoft’s Windows blank-screen steps. If no logo appears with minimal hardware, Windows repair commands cannot help; the failing component needs hardware diagnostics or service.