Back button not working?

[Android Central Question]

My phone is a Samsung Galaxy J3 Luna Pro. Out of nowhere last night, the back button stopped working, and its behavior would shift sporadically. Sometimes I'd have to press down especially hard to get it to register, sometimes it wouldn't register at all, sometimes it would register without me even pressing it. I tried restarting my phone and, initially, that seemed to fix the problem; but come this morning and it's still not working, and restarting my phone didn't fix the issue this time.

I read online that the J3's back button is a touch key, and that it should be lighting up; but neither that nor the app drawer button have ever lit up, and there are no options in the Settings menu to modify any touch key lights.

I even tried booting the phone into Safe Mode to see if an app was causing the problem, but I was facing the same issues even then, so it can't be an app. Really worried that something major is messed up with my phone and that I'll have to replace it. Any ideas as to what's going on?

 

[B. Diddy]

Welcome to Android Central! I can't find any specific mention on the web, but from looking at some videos about the J3 Luna Pro, I don't think the capacitative buttons light up. Cheaper phones might omit this feature. My old ASUS Zenfone 2 also had buttons that didn't light up.

Do you have a screen protector on? If so, does it cover the buttons?

It may very well be a hardware fault -- these budget phones tend to have more quality control issues.

 

[Skirdus]

Welcome to Android Central! I can't find any specific mention on the web, but from looking at some videos about the J3 Luna Pro, I don't think the capacitative buttons light up. Cheaper phones might omit this feature. My old ASUS Zenfone 2 also had buttons that didn't light up.

Do you have a screen protector on? If so, does it cover the buttons?

It may very well be a hardware fault -- these budget phones tend to have more quality control issues.

I had one on at the time it started malfunctioning. Was wondering if that played a role in the issue so I took it off, only to find that it seemingly had no effect, so I've left it off ever since.

I can still use the back button's feature via the Assistant Menu, but occasionally it will still rapid-fire out of nowhere, so I'm hoping to at least fix that issue if possible.

 

[B. Diddy]

Does it only happen when the phone is plugged in and charging?

 

[Skirdus]

Not to my knowledge, no. And it's definitely very random, considering I've been using it for the past few hours and no such instance has occurred; but come a while later, and it will happen out of nowhere just like before.

Edit: Can confirm, it happens even when the phone isn't plugged in.

 

[B. Diddy]

The only other options I can think of apart from getting a replacement would be to do a factory reset or reinstall the firmware, in case this is a firmware bug. You can try reinstalling the firmware using Smart Switch (http://www.sammobile.com/forum/showthread.php?t=29914) or Odin: http://forums.androidcentral.com/am...w-flash-stock-rom-via-odin-new-interface.html