howtosimply.com/guides/samsung-galaxy-mobile-data-not-working-7-fixes/ · Checked October 2026 · Samsung Galaxy A57 (One UI 9, Android 17 (build A576BXXU6BZIE)) and Samsung Galaxy A57 5G (One UI 8.5, Android 16)

In this guide

Check Mobile data in the quick panel
Open Connections
Check Airplane mode
Check the Mobile data switch and limits
Abroad? Check Data roaming
Restart the phone
Reset mobile network settings
If this does not work
Good to know
Sources

Quick answer

Swipe down from the top and check that Mobile data is on and Airplane mode is off. Then check Settings, Connections, Data usage, Mobile data, and Data roaming if you are abroad. Restart, then reset the mobile network settings under General management, Reset. Still failing? Ask your carrier.

7 of 7 steps with real screenshots · 1 official source below

Device: Android
Shown on: Samsung Galaxy A57 (SM-A576B), One UI 9, Android 17 (build A576BXXU6BZIE), Samsung Galaxy A57 5G (SM-A576B), One UI 8.5, Android 16
Starts in: Quick Settings
Real screenshots: 7 of 7 steps
Our phone: Shown on Galaxy A57, One UI 8.5
Checked: October 2026
Sources: 1 official, linked below

Step by step

Check Mobile data in the quick panel
Swipe down from the top of the screen and check that Mobile data is on. While you are there, make sure Airplane mode is off.
In our quick panel Airplane mode and Mobile data are tiles in the same row.
Done
Open Connections
Open Settings and tap Connections.
Done
Check Airplane mode
Airplane mode must be off, or the phone has no mobile connection at all.
Done
Check the Mobile data switch and limits
Tap Data usage. The Mobile data switch must be on. Data saver and Billing cycle and data warning, on the same page, show whether you have limited data use. Data saver read Off on our phone.
Done
Abroad? Check Data roaming
Back in Connections, tap Mobile networks. Outside your home country, mobile data only works with Data roaming switched on. Roaming can cost extra; check your tariff first.
Done
Restart the phone
Hold the Side key and the Volume down key together. Ours showed Power off, Restart, Emergency call and Medical info: tap Restart. A restart re-registers the phone on the network.
Done
Reset mobile network settings
Open Settings, General management, Reset and tap Reset mobile network settings. It restores the mobile network options to their defaults; apps and files stay. On the confirmation screen tap Reset settings.
Done

If this does not work

You recently changed carrier Samsung says that if you kept the same phone, the new carrier may need to reset it for its network. Contact them. Source: Why is mobile data not working on my Samsung phone
The phone is frozen or very slow to respond Samsung says to force restart: hold Volume down and the Side key together until the screen turns off, then hold them again until the Samsung logo appears. Your data stays. Source: Why is mobile data not working on my Samsung phone

About this guide

When Wi-Fi works but mobile data does not, the cause is usually a switch, a data limit or a network setting rather than a broken phone. Work through these in order.

Steps 1 and 6 are from the same phone after its One UI 9 update (Android 17).

Good to know

Older Samsung pages call this option Reset network settings. On One UI 8.5 it is split into Reset mobile network settings and Reset Wi-Fi and Bluetooth settings.

If none of this works, the problem may be coverage, your plan or the SIM: contact your carrier.

Battery worries after turning things off and on: Samsung Galaxy battery draining fast? 6 fixes.

In short: Quick panel: Mobile data on, Airplane mode off. Settings, Connections, Data usage and Mobile networks (roaming). Restart. General management, Reset, Reset mobile network settings. Then your carrier.

Sources