TV Boxes

Android TV box says no signal: HDMI and power checks

How to separate a TV input issue from a failed adapter, bad power supply, or unsupported resolution.

Quick answer

Start with the least destructive check, confirm the device state, and only then change settings. For this problem, the fastest route is usually: Select the exact HDMI port in the TV input menu. Test a different HDMI cable. Use the original power adapter when possible.

Before you start

  • Select the exact HDMI port in the TV input menu.
  • Test a different HDMI cable.
  • Use the original power adapter when possible.
  • Reset video resolution if the box boots but stays blank.

Prove the TV input first

A no-signal message usually comes from the TV, not the box. Open the TV input menu and select the HDMI number printed beside the port.

If another device works on the same port and cable, the box or its power supply is the next suspect.

Check power stability

Cheap power adapters can light the box LED but fail during boot. Use the rated adapter and avoid powering the box from the TV USB port unless the manual allows it.

If the box restarts repeatedly, power is more likely than HDMI.

Reset display output

Some boxes remember a resolution the current TV cannot show. Try a reset button, recovery menu, or a different TV to change output to 1080p.

After the screen returns, disable unsupported refresh rates before reconnecting to the original TV.

Symptom checklist

What you seeMost likely causeFirst safe action
The device reacts, but the result is wrongWrong input, profile, mode, or account stateConfirm the visible setting before resetting anything
Nothing reacts at allPower, cable, port, battery, or button issueTest with a known good power source or cable
The problem comes back after rebootSaved setting, weak signal, low storage, or failing accessoryChange one variable and write down what changed

FAQ

Can an HDMI cable fail partly?
Yes. A cable may work at 720p but fail at 4K or higher refresh rates. Testing at 1080p is a useful diagnostic step.
Why does the logo show and then disappear?
The boot logo may use a basic resolution, then the system switches to an unsupported mode. Reset display settings or test another screen.

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