HDMI No Signal PC

Step-by-step checks before you replace parts

Laptop HDMI no signal on an external monitor

Laptop lid open or closed, external monitor shows HDMI no signal. Projection mode and the physical HDMI/USB-C path are the usual fixes.

Check this first: Does the laptop’s built-in screen show Windows? Yes → focus on external path (Win+P, cable, dock). No → use blank-screen steps on the internal panel first, then retest HDMI.

Steps

  1. Direct cable, no dongle

    Connect HDMI (or USB-C DisplayPort Alt Mode) directly. Remove hubs for the first pass — see dock / USB-C if you must use one.

  2. Win+P while the external is connected

    Try Duplicate, Extend, and Second screen only. For lid-closed desk setups, Second screen only is often required.

    Laptop and external monitor with Win+P projection modes listed and Extend highlighted
    Cycle Win+P modes with the external monitor attached.

  3. Graphics driver reset

    Win+Ctrl+Shift+B, then Detect in Display settings.

  4. Advanced: discrete GPU HDMI on some gaming laptops

    Some models wire HDMI to the dGPU. Ensure the dGPU is active in the vendor control panel and that Windows power settings are not disabling it. Prefer OEM instructions for your model.

What to do next

Built-in screen OK, external dark Stay on this page + cable/dock pages.
Both screens dark Hold the power button for about 10 seconds, unplug the charger and any dock, reconnect the charger only, and power on. Then use Win+Ctrl+Shift+B. Leave the case closed — desktop steps such as reseating RAM or removing a graphics card do not apply to a laptop. If the built-in panel stays black, follow Microsoft’s blank-screen guide.

FAQ

HDMI worked yesterday on this laptop

Recheck Win+P (mode may have changed), cable, and any new dock. Then reset the graphics driver.

USB-C monitor only

Confirm the port supports DisplayPort Alt Mode. Charging-only ports will not drive a display — dock guide.

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.