Short answer: No Signal means the monitor is powered but receives no usable video. The cause may be the selected input, cable, dock, graphics output, sleep state, or computer startup.
This guide uses low-risk checks first, keeps account and personal data protected, and helps you identify whether the problem belongs to the device, app, network, or service.
What usually causes this problem
Select the correct input, reseat the display cable, and test one known-good cable and port before changing software settings. Common causes include:
- Monitor is on the wrong input.
- Cable is loose or damaged.
- USB-C port lacks video output.
- Computer did not wake or boot.
Change one thing at a time. If several settings are changed together, it becomes difficult to know which step actually solved the problem or created a new one.
Fix it in the safest order
- Choose the matching HDMI DisplayPort or USB-C input. Complete the check, then test the original symptom before moving to the next step.
- Power off both devices. Complete the check, then test the original symptom before moving to the next step.
- Reconnect the cable firmly. Complete the check, then test the original symptom before moving to the next step.
- Remove docks and adapters for one test. Complete the check, then test the original symptom before moving to the next step.
- Try another supported port. Complete the check, then test the original symptom before moving to the next step.
- Test the monitor with another source. Complete the check, then test the original symptom before moving to the next step.
Protect your data while troubleshooting
Do not force a connector or assume every USB-C port carries video. Back up irreplaceable files before clearing storage, resetting settings, removing an account, reinstalling an app, or formatting a drive. Use official apps and support pages rather than download links sent through pop-ups, comments, or unexpected messages.
For users in the Philippines, also check whether the issue changes between home Wi-Fi and mobile data. Prepaid balance, carrier maintenance, local power interruptions, and ISP outages can resemble a device problem. Avoid repeated resets when the service itself is unavailable.
How to confirm the fix
The monitor shows the startup screen and reconnects correctly after sleep. Repeat the test after one normal restart. A workaround that succeeds once but fails immediately after reboot is not a complete fix.
When to get official help
Seek hardware support if no known-good source works or the monitor shows damage. Before contacting support, note the device model, operating-system version, app version, exact error text, time of failure, and the steps already tested. Never send a password, one-time code, recovery phrase, or full payment-card number.
