External monitor showing No Signal when connected to your Mac
The monitor isn't getting a signal because the cable connection is loose, the port needs cleaning, or your Mac's display settings don't recognize the monitor. Unplug the cable from both ends, check for dust, plug it back in firmly, and your Mac should detect it within 10 seconds.
When a monitor shows No Signal, your Mac isn't sending video through the cable. This happens when the connection is loose, the port is dirty, or the cable isn't in the right port. Disconnect and reconnect firmly, check for dust in both ports, and give your Mac a few seconds to recognize the monitor.
- ✓Have access to both the Mac and monitor
- ✓Know where the ports are on both devices
- ✓Have 5–10 minutes for troubleshooting
Fix-IT-Bot will walk you through each step, just tap, no typing needed.
Skip, I just want a technicianCommon mistakes to avoid
- Not plugging the cable in firmly enough. It needs to click or seat completely on both ends
- Plugging an HDMI cable directly into a Mac that doesn't have an HDMI port. Newer Macs need an adapter
- Assuming the monitor is broken when the real problem is a loose cable or dirty port
Signs you need professional help
- The monitor shows No Signal even after you've reconnected the cable and restarted your Mac
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