How to fix Samsung Galaxy J7 Prime that has drained battery, black screen and flashing blue light [Troubleshooting Guide]

A drained battery would surely give you a black screen because in this case, the phone is turned off. This goes to say that it would also be impossible for the LED notification to flash because there’s not enough battery to power it up. Charging the phone should be the first thing you need to do if it appears that it’s totally powered off. However, if you’re seeing a blue light flashing even if the phone appears to be powered down, then most likely, your phone is just experiencing what we call a “system crash.”

We’ve seen cases wherein third-party apps started to crash and affected the overall performance of the firmware. As a result, owners noticed their devices became so slow until the point where they no longer power on or respond. Firmware updates may also cause a system crash if some of the files got corrupted. Then, there’s also a possibility that due to a hardware issue, the firmware gets stuck on a black screen. Needless to say, it would be a lot difficult to determine what the problem with your phone that only has a black screen.

In this post, I will tackle this problem with the Samsung Galaxy S7 Prime being the subject of the troubleshooting. We will try to rule out every possibility until we can determine what the problem really is and formulate a solution that might fix it for good. So, if you’re one of the owners of this phone and are currently having the same problem, continue reading below as this post maybe able to help you.

Before anything else though, if you have other issues with your device, then visit our Galaxy J7 troubleshooting page for we have already addressed several common problems with this phone. Odds are that there are already existing solutions to your problems so just take time finding issues that are similar with yours. If you can’t find one or if you need further assistance, feel free to contact us by completing our Android issues questionnaire. Please provide us with as much information as possible so that it would also be easier for us to troubleshoot the problem. Don’t worry as we offer this service for free, so all you have to do is give us sufficient information about the problem.

How to troubleshoot Galaxy J7 Prime with black screen, blue light flashing

Problem: J7 Prime drained battery, blue light flashes and won’t charge or switch on. Non-removable battery. Tried to charge with a laptop but it won’t recognise it.

Troubleshooting: There’s not much we can do about a phone that won’t turn on or charge. What we can right now is try everything we can to make the phone turn on again so that we can troubleshoot it. Here’s what you need to do…

Step 1: Do the forced reboot procedure

If your phone has a black screen, unresponsive but you can see the notification light flashing, it might be just a crash and this might be the only thing you need to do. It refreshes your phone’s memory and it’s actually equivalent to the battery pull procedure we often do to phone with removable batteries. Since your J7 Prime doesn’t have a removable battery, just press and hold the volume down and power keys to simulate battery disconnect. Your phone may boot up normally after you did this. But move on to the next step if the phone refused to power up.

Step 2: Try starting your phone up in Safe mode

If this problem is due to a third-party app or two, then your phone will be able to start in safe mode without having any problems. When in safe mode, all third-party apps are temporarily disabled and while booting the phone in such environment alone won’t fix the problem, it still very helpful to isolate the problem:

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.

If you’ve successfully brought your phone to start in this mode, then it’s clear your third-party apps have something to do with the problem. However, try to reboot your phone in normal mode to see if it goes through this time but if not, then find the app that’s causing the problem and then uninstall it:

1. From the Home screen, tap the Apps tray.
2. Tap Settings > Apps.
3. Tap the desired application in the default list or tap 3 dots icon > Show system apps to display pre-installed apps.
4. Tap the desired application.
5. Tap Uninstall.
6. Tap Uninstall again to confirm.

On the other hand, if the phone can’t boot up in safe mode successfully, then try the next step.

Step 3: Try to start your phone in Recovery mode

The Android system recovery is the fail-safe of almost all Android devices. Even if your phone has a serious firmware issue, it may still be able to start in this mode provided there’s no issue with the hardware.

If you can make your phone to boot up in this mode, then we’re already halfway to fixing the problem but if not, then it’s possible the issue is with the hardware. But assuming the phone starts in recovery mode, you can try wiping the cache partition to delete all system caches. There are times when caches get corrupted and result to various performance-related issues. If the wiping of the cache partition won’t work, then you have to do the Master reset.

How to start your J7 Prime in Recovery mode and wipe cache partition

1. Turn off the device.
2. Press and hold the Volume Up key and the Home key, then press and hold the Power key.
3. When the Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds, then ‘No command’ 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 to highlight “yes” and press the Power key to select.
7. When the wipe cache partition is complete, “Reboot system now” is highlighted.
8. Press the Power key to restart the device.

How to boot your phone in recovery mode and do the master reset

1. Turn off the device.
2. Press and hold the Volume Up key and the Home key, then press and hold the Power key.
3. When the Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds, then ‘No command’ before showing the Android system recovery menu options).
4. Press the Volume down key several times to highlight “wipe data / factory reset.
5. Press Power button to select.
6. Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
7. Press Power button to select and start the master reset.
8. When the master reset is complete, “Reboot system now” is highlighted.
9. Press the Power key to restart the device.

After doing all this and the phone still refuses to turn on, then bring it to the shop and let the tech run some tests to determine what the problem really is.

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