If your tablet shows no signal, shows bars but no 4G/LTE icon, or displays a "No Cellular Data Received" type error, this article walks through the most common causes and how to fix each one.

Symptoms

• No signal bars, or an X over the signal icon
• Signal bars are showing, but no 4G or LTE icon appears
• "Security policy prevents use of unsecure Wi-Fi Networks" error
• "No Cellular Data Received" or similar connectivity error
• The tablet was working fine and suddenly lost connection

Process Checklist

• Step 1 – Confirm mobile data is turned on 

• Step 2 – Check the SIM card 

• Step 3 – Check APN settings 

• Step 4 – Check for a reached data limit 

• Step 5 – Run a mobile data test 

• Step 6 – Rule out Wi-Fi security settings

Step 1 – Confirm Mobile Data Is Turned On

Go to Settings > Connections > Data Usage > Mobile Data and confirm it's switched on.

Step 2 – Check the SIM Card

If mobile data is already on and you still have no signal bars at all:

1. Power off the tablet.
2. Use the SIM-eject tool that came in the tablet's box to open the SIM tray.
3. Confirm the SIM card is seated correctly and facing the right direction.
4. Reinsert the tray.
5. Power the tablet back on.

A SIM card that's slightly loose or not fully seated can cause a total loss of signal, even when everything else in Settings looks correct. If Mobile Networks doesn't appear at all under Settings > Connections, that's often a sign the SIM isn't seated properly — recheck it using the steps above.

If the signal still doesn't return, this may require reactivating or replacing the SIM.

Step 3 – Check APN Settings

If you see signal bars but no 4G or LTE icon, your Access Point Name (APN) may be set incorrectly.

Go to Settings > Connections > Mobile Networks > Access Point Names and confirm the APN matches your carrier:

Step 4 – Check for a Reached Data Limit

If your data plan has hit its usage limit for the billing period, the tablet will lose cellular service even though everything is configured correctly.

Step 5 – Run a Mobile Data Test

Use the OpenSignal app (installed on the tablet's second home screen) to confirm the SIM is actually communicating with the network:

1. Turn Wi-Fi off: Settings > Connections > Wi-Fi.
2. Open OpenSignal and allow the requested permissions.
3. Confirm the top-left of the app shows a mobile data connection (it will display "Wi-Fi" instead if you're still connected to Wi-Fi).
4. Tap the large green speed test button to run the test.
5. When the test finishes, tap Indoor or Outdoor depending on where you ran it.
6. Turn Wi-Fi back on and reconnect to your usual network.

If you're inside a metal building, step outside before testing — building materials can block cellular signal entirely and produce a false result.

Step 6 – Rule Out Wi-Fi Security Settings

If you see the error "Security policy prevents use of unsecure Wi-Fi Networks," the tablet requires a minimum of WPA (or WPA2) security on the Wi-Fi network it's connecting to. This typically starts happening after a Wi-Fi router is replaced, factory reset, or reconfigured without a password.

To resolve: update your Wi-Fi router to use WPA or WPA2 security with a password, then reconnect the tablet to that network using the new password. If you are unable to update the Wi-Fi setting yourself you will likely need to contact your school or district IT department and tell them you are unable to connect to the local Wi-Fi network, provide them with the error message and let them know the network must have a minimum of WPA or WPA2 security for the tablet to connect. 

July 14, 2026 20:19