Search guides

Fix a modem that shows no light

We'll check power, outlet, and cable—so the modem gets power and shows lights or we tell you when to call support.

Troubleshooting · Wi‑Fi & networking
5–15 min
What you'll need
  • Modem
  • Power cable and adapter
Step 1 of 5

Quick triage — pick your path

Quick triage — pick your path

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

Show full guide

Steps

Goal: Check power, outlet, and cable so the modem gets power and shows lights.

  • Confirm the outlet has power. Check for a switched outlet.
  • Confirm the power adapter is firmly connected to the modem and the wall.
  • Try a different outlet or power cable.
  • Good: The modem shows lights. Bad: The modem still shows no light—call support.

Outlet check

Goal: Confirm the outlet has power.

  • Test the outlet with another device. Check if a switch controls it.
  • Good: Outlet has power. Bad: No power—try different outlet.

Cable check

Goal: Confirm the power cable and adapter are connected.

  • Check both ends of the power cable. Check the adapter at the modem.
  • Good: Cable connected. Bad: Loose—seat firmly or try different cable.

When to get help

Call the manufacturer or your ISP if:

  • The modem still shows no light after checking power and cables.
  • The power supply or modem may be faulty.

Verification

  • The modem shows at least one light (power or status).
  • The modem boots and attempts to sync (if it has sync lights).
  • No burning smell or damage to the adapter.

Escalation ladder

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

  1. Check outlet Confirm outlet has power, not switched off.
  2. Check cable Confirm power cable and adapter firmly connected.
  3. Try different outlet/cable Test with different outlet or power cable.
  4. Call support Power supply or modem may be faulty.

What to capture if you need help

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

  • Modem model
  • Power adapter model
  • Steps already tried

Does the outlet have power?

No power means no lights.

Test the outlet with another device. Check for a switched outlet. Good: outlet has power. Bad: no power—try different outlet or fix switch.

Yes No

You can change your answer later.

Fix outlet

Try a different outlet. Or turn on the switch for a switched outlet. Check if the modem powers on.

Done

Is the power cable and adapter firmly connected?

Loose connections prevent power.

Check the power adapter at the modem and wall. Good: firmly connected. Bad: loose—seat firmly and try again.

Yes No

You can change your answer later.

Connect cable firmly

Seat the power cable and adapter firmly. Wait a minute. Check if lights appear.

Done

Wait a minute and check again

Some modems take 30–60 seconds to show lights. Good: lights appear. Bad: still no lights—try different cable/adapter, or call support.

Done

Reviewed by Blackbox Atlas

Rate this guide

Was this helpful?

Continue to