How to fix a Galaxy J5 mobile data that keeps disconnecting [troubleshooting guide]

Hello and welcome to our #GalaxyJ5 troubleshooting article. Today’s post focuses on three connection issues that commonly occurs on this device. If your J5 has connectivity issues, we suggest that you check our solutions below, even if the circumstances in your case are different.

Problem #1: How to fix a Galaxy J5 mobile data that keeps disconnecting

I have a Galaxy J5. My issue is that Internet (or data) goes off and on. It’s not because of my location because it does this everywhere. An example is that this morning I was able to download an app but after an hour or 2 it stopped again. Whenever it goes off it doesn’t come back on for a while (as in, it’s off more than it’s on). When I am connected to WiFi, there are no problems. When I am just relying on my data, it won’t work. — Casey F.

Solution: Hi Casey. If you’re positive that the issue occurs even when your phone has excellent signal reception (full signal bars), these are the troubleshooting steps that you can do to resolve the issue:

Force restart your J5

The first basic troubleshooting step that you want to do in this case is to ensure that you refresh the system by restarting it. Here’s how to do it:

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.
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.

Clear network settings

It’s possible that this problem is caused by incorrect network setting or configuration only so the next troubleshooting that you want to do is to reset all network settings. This affects both the wifi and mobile data connections so be sure that you know how to connect your J5 back to the wifi networks before you proceed. If you are using a VPN connection, this troubleshooting step will also erase your VPN information so again, you want to ensure that you know how to set it up before doing it.

To reset the network settings on your J5:

Open Settings app.
Tap General management.
Tap Reset.
Tap Reset network settings.
Tap RESET SETTINGS button.
Restart your S9 and check for the problem.

Reseat SIM card

Some Android users were able to find success in fixing network issues in the past by removing their SIM card. While that may sound pointless, there’s actually an explanation for it. When you remove then insert a SIM card to a device, you’re actually forcing it to reconfigure the cellular settings. In some cases, this is reason enough to fix a network bug. We don’t know if this will work in your case but there’s no harm in trying it. Basically, what you want to do is to remove the SIM card from your phone and re-insert it while the phone is ON. Once inserted, your J5 should check the current cellular settings in the background and change them if necessary.

Replace SIM card

Should re-inserting the SIM card won’t help, the next good thing to do is replace it with a new one. Although SIM cards seldom go bad under normal use, there’s still a small chance that yours may be defective. Most carriers will allow you replace the SIM card for free but if yours won’t getting a new one will not be that much anyway so go ahead with it.

Observe in safe mode

We don’t know much about your particular device’s history so there’s no way for us to say with this certainty but sometimes, bad apps do cause problems with a system. To check if you downloaded one such app, you need to run your J5 to safe mode and observe it. If cellular data connection works fine in this mode, you can assume that one of your apps is causing the problem.

Here are the steps on how to boot your phone to safe mode:

Turn the device off.
Press and hold the Power key past the model name screen appearing on the screen.
When SAMSUNG appears on the screen, release the Power key.
Immediately after releasing the Power key, press and hold the Volume down key.
Continue to hold the Volume down key until the device finishes restarting.
When Safe mode appears in the bottom left corner of the screen, release the Volume down key.
Let your phone run and try to replicate the problem. If voice calling works properly, you have a bad app issue at hand.

If you think that there’s an app issue, you can try to identify it by following these steps:

Boot to safe mode.
Check for the problem.
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.
After you uninstall an app, restart the phone to normal mode and check for the problem.
If your J5 is still problematic, repeat steps 1-4.

Restore all software settings to their defaults

Factory reset is your ultimate method of knowing whether or not the root of the issue is on the software side. As the name suggests, factory reset will return all software setup to their defaults. Make sure to check for the problem right after you factory reset the device to see any difference. Be sure not to install anything before you observe the phone.

To factory reset your J5:

Make a backup of your personal data.
Turn off the device.
Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
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).
Press the Volume down key several times to highlight ‘wipe data / factory reset’.
Press Power button to select.
Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
Press Power button to select and start the master reset.
When the master reset is complete, ‘Reboot system now’ is highlighted.
Press the Power key to restart the device.

What to do if factory reset fails?

Ideally, you should no longer reach this point in your troubleshooting unless nothing happens after a factory reset. If the mobile data continues to drop randomly even after you wiped the phone, there are two possible reasons for that. One is the possibility that your phone has hardware problem, and the other is there’s a network issue going on.

Both of these issues are beyond any average user’s ability to fix so you either have to call Samsung or let your network operator know of the problem. If your phone was provided by your carrier, we suggest that you contact them for support instead of going directly to Samsung. Some carriers have their own replacement program so you’re better off using that.

Problem #2: Galaxy J5 keeps disconnecting from Chromecast

My Samsung J5 keeps losing connection to Chromecast. I have connection when I restart the router. Sometimes just for a few minutes. It does not help restarting the phone only or the Chromecast only. Sometimes my Wi-Fi symbol has a little exclamation mark next to it on the right side, but my internet connection works fine all the time, regardless is the symbol is there or not. (I may have resolved this just now by forgetting and adding the Wi-Fi, but it didn’t help). I just had new internet and router installed when this issue started. Before this, I have used the same Chromecast for a year without any problems. My girlfriend’s Huawei works fine and she connects without any issues. — Troels Bovbjerg

Solution: Hi Troels. An issue like this is very complicated so there may be very little that we can do about it. The issue may lie on the router, on the Chromecast device, on your J5, or in the network in general. Based in our own experience with our Chromecast device, it may reboot by itself if it loses sync with the router or with any device casting to it. The loss of sync can be a mystery on its own as it can be a product of a lot factors. As far as Android troubleshooting is concerned, the most that can be done is a factory reset. If that won’t make any difference, then go ahead and troubleshoot your Chromecast or router.

Problem #3: Galaxy J5 won’t connect to wifi after a factory reset, J5 FRP issue

Hi! I recently bought a Samsung J5 off a guy on shpock. He told me he had done a factory reset and to call him if i had any problems. When the phone loads up, it asks you to connect to a wifi. I’ve tried connecting to the wifi but i keep getting an error message along the lines of “unable to sign in to wifi ap. An unauthorised factory reset has been performed on this device. The sign in screen cannot be accessed”. I’ve been scouring the internet to try and find a solution as the guy i brought it off isn’t answering to any of my calls or messages. You can bypass the wifi options page, which it asks for the google account that was previously synced to the device. Obviously, i don’t know the google account or password linked so cannot access the phone at all. I dont know what else to do, at £200 i really hope i haven’t been ripped off. Thanks in advance. — Owen Owen

Solution: Hi Owen. There’s no sugarcoating this but we think you really had been ripped off. Unless the original owner unlocks the phone (enters his/her Google account and password), your device is basically useless. Starting with Android Lollipop, all Samsung phones had been protected by FRP or Factory Reset Protection. FRP blocks any attempt to set the device up after a factory reset by asking for the previously associated Google account credentials. If you can’t provide the username and password, there’s no way you’ll be able to set the phone up again.

The best thing that you can do is to exert all effort to find the guy who sold you the phone and let him or her to unlock it.