Symptoms
- Monitor stays black or says 'no signal'
- Monitor works with other devices
- Chromebook shows monitor is connected but nothing displays
- Extended vs mirrored display confusion
Likely causes
- CommonWrong input source selected on the monitorMany monitors have multiple inputs and need the correct one manually selected.
- CommonFaulty or incompatible cable/adapterNot all USB-C to HDMI adapters support video output; some are charge-only.
- PossibleDisplay settings set to mirror instead of extend, or resolution mismatchIncorrect display mode can make it seem like nothing is happening.
- Less commonChromebook model doesn't support external display outputSome budget models have limited or no video-out support via USB-C.
What to do
- Confirm the monitor is set to the correct input (HDMI 1, USB-C, DisplayPort, etc.) using its menu buttons.
- Try a different cable or adapter, ideally one confirmed to support video, not just charging.
- Go to Settings > Device > Displays on the Chromebook and click 'Detect displays' or similar.
- Check whether the display mode is set to mirror or extend and adjust as needed.
- Test the same monitor and cable with another laptop or device to rule out a monitor/cable fault.
- Check your Chromebook model's specs to confirm it supports external display output over USB-C.
Tools and parts
- HDMI or USB-C cable/adapter known to support video
USB-C to HDMI adapterSearch: “USB-C to HDMI adapter for Chromebook video output”
When to call a pro
Not typically needed; this is almost always solved with the right cable and settings.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.