A second monitor that won't show up has a short troubleshooting checklist. Work through it before raising a ticket.

1. Confirm the monitor itself is alive

Press the monitor's power button. If the monitor has its own input selector (HDMI 1 / HDMI 2 / DisplayPort / VGA), cycle through them — sometimes the OS-detection works but the monitor's on the wrong input.

You should see at least a "no signal" message or the manufacturer's logo. If the screen is completely black with no LED:

  • Try a different power outlet
  • Check the monitor's power LED — is it solid, blinking, or off?

2. Try a different cable

Cables fail more often than you'd think — especially long HDMI runs and cheap braided USB-C. If you can swap with a colleague's, do that first. If the swap works, you've found it.

For USB-C/Thunderbolt cables: not all USB-C cables carry video. The ones that do are usually labeled "Thunderbolt" or "DisplayPort Alt Mode". A charging-only USB-C cable will charge the monitor but won't transmit video.

3. Try a different port

Modern laptops have multiple display outputs (HDMI, USB-C, sometimes DisplayPort). Try a different one. If your laptop has only one output and it's broken, you'll need a docking station — that's a ticket.

4. Force Windows to redetect

Windows + P brings up the projection menu. Try toggling between modes:

  • PC screen only then back to Extend
  • Or Windows + Ctrl + Shift + B to restart the graphics driver (the screen flashes briefly)

Sometimes Windows latched onto a state and won't move; this resets it.

For deeper redetection: right-click the desktop → Display settings → scroll down to Multiple displays → Detect.

5. Update the graphics driver

Out-of-date drivers cause display detection to fail silently:

  • Open Device Manager → Display adapters
  • Right-click your GPU → Update driver

If you have a discrete GPU (NVIDIA, AMD), use the GPU's own update tool, not Windows Update — it's faster and more reliable.

6. Docking station diagnostics

If you're connecting through a dock and the monitor fails:

  • Unplug the dock from the laptop, count to 10, plug back in
  • Try plugging the monitor directly into the laptop (bypass the dock) — if that works, the dock is the issue

Docks die quietly. They're the #1 cause of "second monitor stopped working" tickets.

7. When to ticket

If you've checked the monitor, swapped cables, tried a different port, and updated drivers, raise a ticket with the monitor brand/model, what cable type you're using, and a screenshot of Windows + P.