HDMI No Signal PC

Step-by-step checks before you replace parts

PC turns on but no display

Fans spin, lights are on, but the monitor stays black or says no signal. This page is for a desktop tower. A laptop with both screens dark stays on the laptop HDMI page.

Check this first: Listen for the single short POST beep (if your board beeps) and watch for any manufacturer logo. Logo never appears on any port/cable → BIOS no signal. Logo or Windows was visible earlier today → try Win+P and driver reset first. Steps 4 and 5 open the desktop case; skip them on a laptop.

Steps

  1. Confirm power signs

    Case LED, fans, keyboard Caps Lock toggle. Microsoft blank-screen guidance starts here.

  2. Minimal video path

    One known-good cable into the GPU port, monitor input set correctly, no dock/adapter.

    Simplified diagram PC GPU to monitor with single HDMI cable and red arrows at both ends
    Simplify to one direct digital cable for the first test.

  3. Win+P and Win+Ctrl+Shift+B

    Follow projection modes and driver reset.

  4. Desktop only: reseat RAM when no firmware image appears

    Skip this on a laptop. On a desktop, if BIOS never shows, power off, unplug the PSU, and reseat RAM (one stick in the slot the motherboard manual recommends). Do not reseat RAM if a mouse cursor is visible — Windows is already running.

  5. Desktop only: test onboard graphics vs the GPU

    Skip this on a laptop. On a desktop, if the CPU has graphics, remove the graphics card and test the motherboard HDMI. Otherwise test that card in another desktop, or try a known-good card.

What to do next

Cursor visible on black screen Windows is running — focus on driver/Explorer, not RAM reseat.
No POST logo ever BIOS / hardware video path.

FAQ

PC turns on but no display — is the GPU dead?

Not necessarily. Wrong port, cable, and driver hangs are common. Prove POST on a minimal cable path first.

Should I buy a new monitor immediately?

Test the monitor on another device first via cable & port.

Official sources

Independent DIY troubleshooting. Prefer Microsoft and OEM support articles for model-specific steps. We do not sell one-click fix tools or host driver packs.