How to fix a Galaxy J7 won’t boot up and stuck in boot loop

Hello Android fans! Welcome to today’s #GalaxyJ7 troubleshooting episode. This article will answer some common issues about this device. As usual, all the cases mentioned below are taken from reports we received from some members of our community. We hope you’ll find this article helpful.

Problem #1: Galaxy J7 Prime won’t boot up after screen repair

Hi, recently my husband dropped his Samsung Galaxy just prime phone on tile and shattered the screen. We purchased a generic replacement screen and just semi installed it (minus the glue). As we booted the phone up it would show us the Samsung Galaxy just prime logo, (glimpse of hope) and nothing else. The phone was charged via original cord and is flashing blue notification lights, it also vibrates. The screen obviously works since it clearly shows the logo and we’ve tried soft resetting it just about 15 times since this morning. Finally we tried using the hold power and down and home key to get to the download page and it shows us the warning page etc. We restarted the phone once again and it still shows no sign of any other display. The phone was in full working order prior to the removal of the original cracked screen. I was very careful in removing the glued on screen. My husband thought he had backed everything up, but sadly there were several folders that stayed behind in the internal storage that was of our daughter’s birthday party and a few old baby photos. The phone does not turn off, can’t really do it. And the backlight of the screen constantly lights up showing nothing. I’ve read through all if not most posts and videos and these have not solved the issue. Please please help! And thank you for your time.

Solution: For smartphones, the screen is not just for displaying images but also as a gateway to the operating system. If it’s not fully functional, there’s no way to access the contents of the storage device. In desktop computers and laptops, a user can simply physically disconnect the hard drive or SSD and plug it to another machine to access the contents. You can’t do that for smartphones. The flash memory that keeps the OS and data are bound more deeply to the motherboard that even if you physically separate the Nand and connect it to another motherboard, the data will still be locked out.

Apparently your problem also goes beyond the screen itself because it also looks like the phone does not boot up normally at all. Assuming you’ve done the screen repair or replacement properly, there may still be other hardware malfunction that prevents the OS from booting up. What that other hardware malfunction can’t be determined by us. You want to let a trained technician run the diagnostics for you so the point of failure can be identified.

Problem #2: What to do if Galaxy J7 drains battery fast and keeps rebooting when battery is low

Hi. My issue has been partly resolved already but is seriously starting to frustrate me. The issue is that my phone the Samsung Galaxy J7 will run out of battery when it was just on 40% or sometimes even higher. At times I find myself playing a game or reading a group chat glance up at my percentage and see it’s at 43% and then 2 minutes later it blacks out and find that it has no power. Previously I mentioned I fixed one of the other issues that went along with this.

The other issue was the fact that my battery would drain super fast despite being in power saving mode and closing all the background apps. So I resorted to factory resetting my phone which has actually fixed the drain issue but the issue of the random power outage still persists. I have no clue and I’m desperate to try anything that could help me as I’m sure you can agree 40% on my phone is now my new 0% as I frantically look for my charger when I see it hit the 40s. Id appreciate any kind of help.

Solution: The most likely reason for both of these problems is poor battery capacity. Lithium-based batteries usually show signs of significant battery degradation a year after manufacture. The more you use it, the faster it loses battery capacity. Both issues are consistent  signs of a spent smartphone battery. The best thing that you can do now is to replace it. Since you’ve already tried a factory reset without apparently fixing the issue, we will no longer recommend a battery calibration. In the event that you want to try it though, here’s what you need to do:

1. Drain the battery completely. This means using your device until it powers down by its own and the battery level reads 0%.
2. Charge the phone until it reaches 100%. Be sure to use original charging equipment for your device and let it charge up completely. Do not unplug your device for at least two more hours and also don’t use it while charging.
3. After the elapsed time, unplug your device.
4. Restart the device.
5. Use your phone until it completely runs out of power again.
6. Repeat steps 1-5.

Should there be no significant improvement in battery performance after calibration, replace the battery with an official one.

Problem #3: How to fix a Galaxy J7 won’t boot up and stuck in boot loop

My phone recently shut off on its own, then I tried turning it back on but the screen remained black. I plugged it in and it suddenly went to the “Samsung Galaxy J7 Powered by Android” screen, and then it went black again, then back to the Android screen, and it kept on switching between those screens. I plugged it and unplugged it a few times and then it went to the normal battery percentage screen, after which it booted correctly. A few minutes later the same happened. In recovery mode (which I couldn’t get to always because in that screen loop there was literally nothing I could do), I did a factory reset and wiped the cache. After a few days, the problem returned. What can I do?

Solution: Since a master reset did not fix the problem for good, the issue is most likely due to poor battery performance. Your J7’s battery may had been depleted so bad that it can only provide barely enough power to stay on. This is usually expected if the voltage has dropped significantly. Boot up requires stable power because the system needs a burst of energy to power up everything. If battery power dips during boot up, the system will crash and eventually returns to the initial boot up process. This is the reason why boot loop issues such as yours tend to happen with older devices sporting old batteries. If the phone is no longer within its warranty period, we suggest that you replace the battery first. As long as you did not tamper with the software by rooting or flashing, there’s a big chance that you’ll fix the issue this way.

Problem #4: Galaxy J7 Prime won’t charge, not detected by PC

My phone is Samsung Galaxy J7 Prime, SM-G610Y/DS. I have encountered the following problems: 1. My phone won’t charge sometimes. 2. My phone can’t connect to a laptop through a micro usb cord. (Previously works) 3. Sometimes my screen would reverse in portrait mode when flipped upside down. 4. When I turn off my phone when it doesn’t charge, a gray battery with lightning is shown but it still won’t charge. I’ve tried to turn on the low battery dump but still not factory reset. I have to hypotheses for the problem 1. I used a charging power cord from a portable speaker to connect my phone to the laptop, since then it wont charge normally. 2. A software update was recently installed in my phone. I wish for a response and thank you for helping me 🙂

Solution: Problems 1, 2 and 4 are most likely related and has the same cause. If you haven’t tried to factory reset the device yet, we suggest that you do it to see if software bug is to blame. For reference, these are the steps to factory reset your J7 Prime:

1. 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.
2. Press and hold the Volume Up key and the Home 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 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.

Should nothing change after a factory reset, you can assume that the charging port may be defective. There’s wisdom why it’s always advisable to only use official accessories like cables and charging adapter for smartphones. Sometimes, third party cables may not be physically fully compatible with a Samsung charging port, causing metal connectors to bend or break when forcing the cable in. Try to examine the charging port using a magnifying tool and see if there’s an obvious damage. If you are unable to do so, let a professional check the hardware.