Samsung Galaxy says "No service"? 6 fixes

By Saadat Rafiq · 2 min read · 6 steps · Updated 5 October 2026

Device

Android

Shown on

Samsung Galaxy A57 5G (SM-A576B), One UI 8.5, Android 16

App

Settings

Real screenshots

4 of 6 steps

Checked

October 2026

Sources

1 official, linked below

Step by step

1. Turn Airplane mode on and off

   Swipe down from the top right and tap Airplane mode (called Flight mode on some phones), wait a few seconds and tap it again. The phone then searches for a network from scratch.

   Done

2. 

   Check the network mode

   Settings, Connections, Mobile networks, Network mode. If it is set to an old mode only, such as 3G where the carrier has switched 3G off, the phone finds no network. Ours was on 5G preferred.

   Done

3. 

   Leave Allow 2G service on

   On the same page, Allow 2G service lets the phone fall back to 2G where nothing faster reaches. It was on on our phone.

   Done

4. 

   Let the phone pick the network

   Mobile networks, Network operators. Switch on Select automatically. A network picked by hand, for example abroad, stays fixed even where it has no signal.

   Done

5. 

   Switch the SIM off and on

   Settings, Connections, SIM manager. Tap the switch next to SIM 1 off, then on again. If the SIM is not listed at all, take it out, check it for damage and put it back.

   Done

6. Reset mobile network settings

   Settings, General management, Reset, Reset mobile network settings. This puts the mobile network settings back to their defaults.

   Done

About this guide

"No service" means the phone is not registered on any mobile network. Before blaming the SIM or the phone, check the network settings: a fixed network or the wrong network mode often causes it after travel or a SIM swap.

The screenshots are from a Samsung Galaxy A57 5G with One UI 8.5 and Android 16. Other Galaxy phones on One UI 8 use the same menus; on older One UI versions a few names and positions differ. Our carrier, phone number and access point name are blurred. We only looked at these screens on our phone and changed nothing.

Good to know

Data not working while calls are fine? Samsung Galaxy mobile data not working? 7 fixes.

If the SIM works in another phone and none of the steps help, ask your carrier whether your line is active and your area has an outage, then have the phone checked.

In short: Airplane mode on and off, a network mode your carrier supports, Select automatically on, SIM 1 off and on, reset mobile network settings.