How to fix Galaxy M40 No Signal | signal keeps disconnecting

Many Android users are frustrated when dealing with No Signal issue on their device.  In this troubleshooting episode, we’ll show you the easy ways to fix your Galaxy M40 No Signal issue.

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How to fix Galaxy M40 No Signal | signal keeps disconnecting

There can be a number of possible factors that you must consider in fixing your Galaxy M40 No Signal issue. Find out the steps that you can do in this situation below.

Galaxy M40 No Signal fix #1: Confirm network is working

Unless there’s obvious reason for you to believe that it’s a device problem, the very first troubleshooting step that you want to do is check for any network-related issue. To do this, try to check if your Galaxy M40 has completely lost all signal bars, or if the bars keep disappearing. In either case, network trouble is most likely the cause. Since you have no control over your network, all you can do is to report the issue to your carrier so they can look into it.

Sometimes, there may be unplanned network outages or maintenance. Be sure to contact your network operator so they can give you firsthand information.

Galaxy M40 No Signal fix #2: Check for intermittent signal issue

Intermittent signal issue can sometimes appear to be total No Signal issue. The former may allow you use network functions for a limited amount of time while the latter won’t at all. If you think that you have an intermittent signal issue, try to relocate to a more open area. This will let you know if the problem is due to poor coverage or interference. If there’s no change and the issue remains, continue with the troubleshooting below.

Galaxy M40 No Signal fix #3: Restart device

If you’ve confirmed that there’s no network problem at all, the next good thing to do is to soft reset your Galaxy M40. We suggest that you try doing the steps below to fully refresh the system:

  1. Press and hold the Power + Volume Down buttons for approximately 12 seconds or until the device power cycles. Note: Allow several seconds for the Maintenance Boot Mode screen to appear.
  2. From the Maintenance Boot Mode screen, select Normal Boot. Note: Utilize the volume buttons to cycle through the available options and the lower left button (below the volume buttons) to select. Allow up to 90 seconds for the reset to complete.
  3. If Maintenance Boot Mode screen won’t show, then your device does not have it. Simply wait for the device to power down completely.

Galaxy M40 No Signal fix #4: Reseat SIM

One of the basic things that you can do when dealing with any network issue is to disconnect the SIM card temporarily. It’s mainly useful if you have a GSM device but can also work even if you have a CDMA phone. Before you disconnect the SIM card, make sure that your device is OFF. This prevents data from being corrupted when a SIM card is suddenly taken out. Make sure to keep the phone off when re-inserting the SIM back.

Galaxy M40 No Signal fix #5: Reset network settings

When you encounter any type of network trouble on a Samsung Galaxy device, one of the troubleshooting steps that you must do is to ensure that you configure all network functions properly. Knowing how to reset reset network settings on Galaxy M40 can come handy if you happen to experience sudden, unexplained problems with wifi, Bluetooth, or mobile data.

When you reset the network settings on your S10, these are the things that happens:

  • Allows background data sync.
  • Clears mobile data limits.
  • Deletes all Wi-Fi SSIDs or wifi names.
  • Disconnects all tethered interfaces.
  • Forgets paired devices.
  • Removes all app data restrictions.
  • Sets network selection mode to automatic.
  • Sets preferred mobile network type to the best available.
  • Turns off Airplane mode.
  • Turns off Bluetooth.
  • Turns off data roaming.
  • Turns off mobile hotspot.
  • Turns off VPN.
  • Turns on mobile data.
  • Turns on Wi-Fi.

Below are the easy steps to clear the current network setup of your device.

  1. On the Home screen, tap Apps icon.
  2. Open Settings app.
  3. Tap General management.
  4. Tap Reset.
  5. Tap Reset network settings.
  6. Tap Reset settings to confirm.

To reset network settings on Galaxy M40 won’t result to loss of your personal data. You can do this safely without worrying that you might lose something important. Hopefully, the steps above will help fix whatever network issue you’re experiencing.

Galaxy M40 No Signal fix #6: Update

Updating your device’s software and apps is one of the effective ways to fix bugs. Some network issues are due to inefficient coding. Make sure to install any pending Android and app updates at this time.

Galaxy M40 No Signal fix #7: Run device on Safe Mode

If your Galaxy M40 No Signal issue started after installing a new app, that can be the reason for the problem. Delete that app and see if it fixes the issue. If you are not sure which of your apps may be causing the problem, restart your device to safe mode. Once in safe mode, check for the problem. If the issue goes away and you can once again use network functions fine, that means you have a third party app issue.

To restart to safe mode:

  1. Press and hold the Power button until the Power off window appears then release.
  2. Touch and hold Power off until the Safe mode prompt appears then release.
  3. To confirm, tap Safe mode.
  4. The process may take up to 30 seconds to complete.
  5. Upon reboot, “Safe mode” appears in the lower-left of the home screen.

Remember that third-party applications are disabled in this mode so what you can use are pre-installed apps. If the issue won’t appear on safe mode, that means that the problem is due to a bad app. Uninstall the app you recently installed and see if that will fix it. If the problem remains, use the process of elimination to identify the rogue app. Here’s how:

  1. Boot to safe mode.
  2. Check for the problem.
  3. Once you’ve confirmed that a third party app is to blame, you can start uninstalling apps individually. We suggest that you begin with the most recent ones you added.
  4. After you uninstall an app, restart the phone to normal mode and check for the problem.
  5. If your Galaxy M40 is still problematic, repeat steps 1-4.

Galaxy M40 No Signal fix #8: Wipe cache partition

Clearing of the cache partition can fix problems in your Samsung device if the reason behind is a corrupted system cache. Android uses this cache to load apps quickly. Sometimes, an update or app installation may corrupt the system cache, resulting to all sorts of issues. To ensure that your phone’s system cache is fresh, try clearing the cache partition. This is how you do it:

  1. Turn off the device.
  2. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  3. When the green Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).
  4. Press the Volume down key several times to highlight ‘wipe cache partition’.
  5. Press Power button to select.
  6. Press the Volume down key until ‘yes’ is highlighted and press the Power button.
  7. When the wipe cache partition is complete, “Reboot system now” is highlighted.
  8. Press the Power key to restart the device.

Galaxy M40 No Signal fix #9: Change network mode

Sometimes, a network trouble can be fixed by temporarily switching from one network operator to another. This forces the phone to reconfigure its network settings, which in effect, helps in clearing bugs. If you haven’t done it yet, here’s how:

  1. Open Settings app.
  2. Tap Connections.
  3. Tap Mobile networks.
  4. Tap Network operators.
  5. Tap Select manually.
  6. Wait for the device to scan the airwaves for other network operators.
  7. Select another network operator (that’s not your own).
  8. Your device should tell you that it fails to register to that network.
  9. After that, select you own network to force the device to register again.
  10. Check for the problem.

Galaxy M40 No Signal fix #10: Factory reset

You may have to resort to a more drastic solution if none of the suggestions above work. This solution is called factory reset. By doing this, you are effectively returning all software settings to their defaults. In this state, the bug that may be causing the problem may be potentially removed. Learn how to factory reset below.

Method 1: How to hard reset on Samsung Galaxy S10 via Settings Menu

This is the easiest way to wipe your Galaxy S10. all you have to do is to go under Settings menu and follow the steps below. We recommend this method if you have no trouble going under Settings.

  1. Create a backup of your personal data and remove your Google account.
  2. Open Settings app.
  3. Scroll to and tap General management.
  4. Tap Reset.
  5. Select Factory data reset from the given options.
  6. Read the information then tap Reset to continue.
  7. Tap Delete All to confirm action.

Method 2: How to hard reset on Samsung Galaxy S10 using hardware buttons

If your case is that the phone is not booting up, or it boots but Settings menu is inaccessible, this method can be helpful. First, you need to boot the device to Recovery Mode. Once you successfully access Recovery, that’s the time that you begin proper master reset procedure. It may take some tries for you before you can access Recovery so be patient and simply try again.

  1. If possible, create a backup of your personal data ahead of time. If your problem prevents you from doing that, then simply skip this step.
  2. Also, you want to make sure that you remove your Google account. If your problem prevents you from doing that, then simply skip this step.
  3. Turn off the device. This is important. If you can’t turn it off, you’ll never be able to boot to Recovery Mode. If you are not able to shut the device off regularly via the Power button, wait until the phone’s battery is drained. Then, charge the phone for 30 minutes before booting to Recovery Mode.
  4. Press and hold the Volume Up button and the Bixby button at the same time.
  5. While still holding the Volume Up and Bixby keys, press and hold the Power button.
  6. The Recovery screen menu will now appear. When you see this, release the buttons.
  7. Use the Volume Down button until you are highlighting ‘Wipe data/factory reset.’
  8. Press the Power button to select ‘Wipe data/factory reset.’
  9. Use Volume Down to highlight Yes.
  10. Press the Power button to confirm factory reset.

Galaxy M40 No Signal fix #11: Get help from carrier

Should nothing fix your Galaxy M40 No Signal issue at this stage, you can assume that the cause is something deep within the system. It can be due to hardware malfunction or failure, serious firmware issue, or network-related bug. There’s no telling which of them might be the true cause. At this point, you need to involve your network operator in trying to figure out the problem. Make sure to let them know of the troubleshooting steps you did including the relevant history that led to the issue.


If you are one of the users who encounters a problem with your device, let us know. We offer solutions for Android-related problems for free so if you have an issue with your Android device, simply fill in the short questionnaire in this link and we will try to publish our answers in the next posts. We cannot guarantee a quick response so if your issue is time sensitive, please find another way to resolve your problem.

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