How to fix Galaxy S9 wifi issue: wifi won’t allow internet connection, can’t cast to Chromecast

We’ve been getting letters from a lot of Samsung Galaxy users regarding their devices being unable to connect to the internet. This troubleshooting article will address wifi and connectivity issues on the #GalaxyS9. We hope you’ll find this article helpful.

Before we proceed, we want to remind you that if you are looking for solutions to your own #Android issue, you can contact us by using the link provided at the bottom of this page. When describing your issue, please be as detailed as possible so we can easily pinpoint a relevant solution. If you can, kindly include the exact error messages you are getting to give us an idea where to start. If you have already tried some troubleshooting steps before emailing us, make sure to mention them so we can skip them in our answers.

Problem #1: Galaxy S9 wifi won’t allow internet connection, can’t cast to Chromecast

I have a new Samsung Galaxy S9.  I am trying to connect to my home wifi. it shows as trying to connect, but it never connects. other devices including my previous phone, laptop and chromecast all connect fine.  I am able to connect my phone to the generic xfinity wifi but not to my home wifi account. I have verified that I am typing in the proper password… what could be the problem? it seems like i have wifi on the phone (when not connected to the xfinity wifi generic account) – I connect to various sites….however, because of this problem I am unable to cast from my phone to my chromecast.

Solution: We don’t know if we’re getting your point exactly but if you’re not sure whether or not your Galaxy S9 is connected to your home wifi, here’s what you need to do:

  1. Turn off mobile data on your phone (if you’re subscribed to one).
  2. Disconnect your S9 from your home wifi.
  3. Reconnect to your home wifi by putting in the correct network passcode.
  4. Once you get the confirmation that phone has been connected to wifi, do a simple test by browsing. You can use any app that requires internet to do that. For instance, if you have a YouTube app, open it and watch a video. If the video works, then you’re connected to the internet.

Once you’ve confirmed that your S9 is connected to the internet using your home wifi, launch Google Home app (the official app to for Chromecast) and reboot your Chromecast. Here’s how:

  1. Open Google Home app.
  2. Tap the Devices icon at the upper right.
  3. Tap the More Settings icon for your Chromecast (this should be the three-dot icon opposite the name of your Chromecast device).
  4. Select Reboot.
  5. Tap OK to confirm the reboot.
  6. Wait for a couple of minutes to allow Chromecast to reboot.
  7. Check if you are now able to cast from apps to your Chromecast.

If you’re still unable to cast at all, you can factory reset your Chromecast to fix it. Here’s how to do that:

  1. Open Google Home app.
  2. Tap the Devices icon at the upper right.
  3. Tap the More Settings icon for your Chromecast (this should be the three-dot icon opposite the name of your Chromecast device).\
  4. Select Settings.
  5. Tap the More Settings icon at the upper right.
  6. Tap Factory reset.
  7. Tap FACTORY RESET at the bottom.
  8. Follow the rest of instructions on your phone.

Factory resetting your Chromecast will reset its settings to defaults and disconnect it from wifi. Be sure to reconfigure it after a factory reset.

What to do if your S9 is unable to connect to your home wifi only

The suggestions above assumes that there’s no problem with your phone and wifi. If the opposite is true, then you need to follow a logical set of troubleshooting steps to know where the problem lies. Be sure to follow our suggestions below.

Force reboot

Sometimes, this simple procedure can fix bugs that developed after the system has run for a long time. By manually forcing your Note8 to reboot, you’re basically simulating a battery pull, which, in older mobiles with removable battery packs, was an effective way to refresh the system. If you haven’t tried this one yet, here are the steps that you can do:

  1. Press and hold the Power + Volume Down buttons for approximately 10 seconds or until the device power cycles. Allow several seconds for the Maintenance Boot Mode screen to appear.
  2. From the Maintenance Boot Mode screen, select Normal Boot. You can use the volume buttons to cycle through the available options and the lower left button (below the volume buttons) to select. Wait for up to 90 seconds for the reset to complete.

Restart your networking equipment

Should rebooting your S9 won’t help, the next step to do is to ensure that you restart your modem and/or router. Simply unplug the power cable for your equipment to turn them off. After 30 seconds, plug them back in and see if your S9 can connect to wifi.

Clear cache partition

Clearing the cache partition is another device troubleshooting step that must be done in this case. At times, updates may corrupt the system cache stored in the cache partition. To ensure that your phone has good working system cache, follow the steps below:

  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.

Verify if bad third party app is to blame

Not all apps are built the same. Some may be coded properly while others may be problematic. To check if one of your apps is to blame, you can reboot the phone to safe mode and observe. If wifi works normally on safe mode, then you know you have a bad app issue.

To boot your S9 Plus to safe mode:

  1. Turn the device off.
  2. Press and hold the Power key past the model name screen.
  3. When “SAMSUNG” appears on the screen, release the Power key.
  4. Immediately after releasing the Power key, press and hold the Volume down key.
  5. Continue to hold the Volume down key until the device finishes restarting.
  6. Safe mode will display in the bottom left corner of the screen.
  7. Release the Volume down key when you see Safe Mode.
  8. Connect to wifi and see if it works.

To identify which of your apps is causing the trouble, you should boot the phone back to safe mode and follow these steps:

  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 S9 is still problematic, repeat steps 1-4.

Reset network settings

This is one of the must-dos in this case. Resetting your S9’s network settings will wipe all wifi networks you’ve previously connected to as well as erase Bluetooth and cellular network configurations.

To return your S9’s network settings to defaults:

  1. Open Settings app.
  2. Tap General management.
  3. Tap Reset.
  4. Tap Reset Network settings.
  5. Tap RESET SETTINGS button to confirm.
  6. Restart your S9 and check for the problem.

Ensure that your phone is not blocked by your router

If you previously tried changing some settings on your router, or if someone in your household did, go over everything and ensure that your phone is not blocked. Routers provided by Internet Service Providers or ISPs often come with built-in user-configurable filters like IP filtering or MAC filtering features. Be sure to check your router’s GUI and see to it that your device is not among the filtered devices.

Refer to your router’s documentation for instructions. Or, you can contact your ISP for support.

Factory reset

As a last S9 troubleshooting step, you may need to wipe the phone if all the suggestions above won’t help. Make sure to back your files up before doing it.

  1. Create a backup of your files.
  2. Turn off the device.
  3. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  4. 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).
  5. Press the Volume down key several times to highlight ‘wipe data / factory reset’.
  6. Press Power button to select.
  7. Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
  8. Press Power button to select and start the master reset.
  9. When the master reset is complete, ‘Reboot system now’ is highlighted.
  10. Press the Power key to restart the device.

Get help from your ISP

Finally, if all our solutions above won’t fix your wifi issue, you should seek help from your ISP. There may be some advanced troubleshooting that you need to unblock or allow your phone to use your router internet connection.

Problem #2: Why a Galaxy S9 won’t connect to a particular network

I received an S9 as a gift from the USA and i’m in Kenya.The phone can’t connect to a 3G or LTE network while else other phones are easily connecting using any network services that is Safaricom, Airtel and Telkom. But sometimes it connects 3G with Airtel. i think it’s by luck but for Safaricom which is the strongest network service in Kenya doesn’t connect to 3G or LTE. I’d really be very grateful if you help me. Thank you in advance.

Solution: If you have a carrier-branded S9, that is, it’s built to work in a particular network in the US like Verizon, AT&T, or T-Mobile, then there’s a chance that it may not be compatible with the networks in Kenya. Even if this phone has been network unlocked properly, that’s not a guarantee that it can work anywhere. For instance, if your phone’s radio is different from devices in Kenya, it may not be able to pick the frequency of networks you’re having problems with. In other words, it’s hardware is simply incompatible with that of the networks you’re having problems with. Try to do some research using Google and find out what your phone’s frequencies are (you can use the phone’s particular model number for this). Once you’ve determined your S9’s operating frequencies, compare it with the carrier’s operating frequencies (may need to contact your carrier for this information). If the frequencies don’t match, that means your phone is not capable of working with that particular network.

Problem #3: What to do Galaxy S9 4G LTE signal is very weak

We have a Samsung Galaxy S9 that rarely has more than 1 bar 4G LTE of signal and sometimes none. Also have a S7 active that has 4 or 5 bars of signal at the same location so I have done a soft reset on the S9 with no improvement in signal. Just wondering what to do next? Just thought y’all might have a suggestion before I do a factory reset. Thanks.

Solution: Signal strength on phones differ, even when they’re on the same location. Try resetting the phone’s network settings and see what happens. Refer to the steps above on how to do this troubleshooting step.

Then, once you’ve reset the network settings, see to it that your phone install any available system updates. If it’s already running the latest Android update, also ensure that all apps are up-to-date.

Sometimes, connection issues are fixed by changing or replacing the SIM card. Visit your carrier’s store and get a new SIM card if needed.

Finally, don’t hesitate to do a factory reset to clear all software information to defaults. If this won’t help either, consider calling Samsung so it can be replaced.


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