Search guides

Fix a TV that has cable box that will not work

We'll check input, cable box, coax, HDMI, and power-cycle—or tell you when to call your provider or a technician.

Troubleshooting · Home electronics
5–15 min
What you'll need
  • TV remote
  • Cable remote
  • HDMI cable
Step 1 of 7

Quick triage — pick your path

Get started

Choose the option that matches what you see. You can jump straight to that section.

Show full guide

Steps

Goal: Confirm the symptom, check input and cable box, then rule out coax and HDMI issues.

  • Confirm the cable box does not show a picture, shows no signal, or will not tune channels.
  • Good: You have confirmed the symptom. Proceed to Check input and cable box.
  • Bad: Cable box works sometimes—may be intermittent.

Check input and cable box

Goal: Confirm the correct input is selected and the cable box is on.

  • Use the TV remote to select the input where the cable box is connected.
  • Confirm the cable box is powered on and not in standby. Wake it with the cable remote.
  • Good: Correct input selected and cable box is on. The signal appears. Done.
  • Bad: Still no signal—proceed to Check coax and HDMI.

Check coax and HDMI

Goal: Rule out loose coax and HDMI connections.

  • Check the coax from the wall is firmly screwed to the cable box CABLE IN port.
  • Reseat the HDMI cable at both ends. Try a different HDMI port and cable.
  • Good: Connections snug. The signal appears. Done.
  • Bad: Still no signal—proceed to Power-cycle.

Power-cycle

Goal: Reset the cable box and HDMI handshake.

  • Unplug the TV and the cable box from power. Wait 30 seconds. Plug both back in. Turn on the cable box first, then the TV.
  • Good: Power-cycle fixes it. The signal appears. Done.
  • Bad: Still no signal—check for service outage or call your cable provider.

When to get help

Call your cable provider if:

  • The coax is connected, the box is on, and you have power-cycled—they can check signal and activation.

Call a TV repair technician if:

  • The cable box works on another TV but not this one, or no HDMI input works on the TV.

Verification

  • The TV shows a picture from the cable box.
  • The correct input is selected.
  • The coax is firmly connected at the cable box.
  • The HDMI cable is firmly connected at both ends.
  • The cable box is on and tuning channels.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Input and cable box Select correct input; confirm cable box is on.
  2. Coax and HDMI Check coax from wall; reseat HDMI; try different port and cable.
  3. Power-cycle Unplug TV and cable box for 30 seconds; plug back in.
  4. Service Check provider for outage or activation.
  5. Call a pro Call provider for signal; call TV technician if box works on another TV.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • TV model
  • Cable box model
  • Cable provider
  • Steps already tried

Is the correct input selected?

Wrong input shows no signal.

Use the TV remote. Select the input where the cable box is connected (HDMI 1, HDMI 2, etc.). Correct input: check that the cable box is on. Wrong input: select correct one, then test.

Yes No

You can change your answer later.

Select correct input

Select the input that matches your cable box (e.g. HDMI 1). Confirm the cable box is on. If signal appears, done. If not, check coax and HDMI.

Done

Is the cable box on and outputting?

Cable box must be on and not in standby.

Check the cable box. Wake it if it is in standby—press a button on the cable remote. Wait for it to boot. On: check coax and HDMI. Off or sleeping: turn it on, then check input again.

Yes No

You can change your answer later.

Turn on cable box and select input

Turn on the cable box. Select the correct input on the TV. If signal appears, done. If not, check coax and HDMI, then power-cycle.

Done

Is the coax from the wall firmly connected?

Coax carries signal to the cable box.

Check the coax at the wall and at the cable box CABLE IN port. Screw it on firmly. Connected: reseat HDMI and power-cycle. Loose: tighten, then test.

Yes No

You can change your answer later.

Connect coax and test

Screw the coax firmly at wall and cable box. Turn on the cable box. If signal appears, done. If not, power-cycle and check with provider.

Done

Reseat HDMI and power-cycle

Unplug HDMI at both ends. Plug back in firmly. Try a different port and cable. Power-cycle: unplug TV and cable box for 30 seconds, plug back in. If signal appears, done. If not, call your cable provider—they can check signal and activation.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a cable box not work?
Wrong input selected, cable box off or sleeping, loose coax or HDMI cable, service outage, or billing issue. Check input, connections, and power-cycle first.
Can I fix a cable box that will not work myself?
Yes. Check input, cable box power, coax and HDMI connections, and power-cycle. Most cable box issues are connection or power related. Call your provider for service or activation issues.
When should I call a technician?
If you have checked input, connections, and power-cycle and the cable box still shows no signal. Call your cable provider first—they can check signal and activation. For TV hardware issues, call a TV repair technician.

Rate this guide

Was this helpful?

Continue to