Notification bar and buttons at the bottom sometimes disappear.

[Luke Hedge]

I am running Android 5.0 on a LG Sunset. Sometimes, when I am watching some videos on YouTube of browsing the internet, the status/notification bar at the top and the buttons at the bottom just randomly disappear and would not come back until a few seconds later or sometimes even longer. During the time that it does this, I cannot do anything with my phone other than power off and hold the power button for more options. I cannot continue scrolling or typing whatever I want to type. But when I'm watching a video, the video continues playing normally.

 

[B. Diddy]

Welcome to Android Central! It's normal in certain apps for the nav and status bars to disappear after a short time -- that's called immersive mode. You can typically bring them back by swiping up a little from the bottom of the screen, or swiping down a little from the top of the screen.

 

[Luke Hedge]

Yes, immersive more does happen, in which I could easily do that. But for my situation, when I try swiping up or down, nothing happens, because like I said before, I cannot do anything other than hold the power button for more options. And also, after things go back to normal, my background for my home screen changes back to the default, in which I have to manually change it back to the one I had previously. It is getting pretty annoying.

 

[B. Diddy]

Hmm, that is pretty odd. Does it happen in Safe Mode as well? LG Sunset LTE L33L - Frequently Asked Questions about resetting your device - HardReset.info

 

[Luke Hedge]

Haven't tried it out yet. I will use it for a day or two and report back.

 

[Luke Hedge]

Alright I don't think it happens during safe mode. I've done the same things like watching videos and it doesn't really happen in safe mode.

 

[B. Diddy]

That suggests that something you installed is causing the issue. The tedious part now is figuring out which app, which means you might have to uninstall them one by one until the problem goes away.

 

[Luke Hedge]

Okay I think CM Locker and maybe CM security as well is causing the problem. I have them already uninstalled and haven't run into the problem so far. Not sure why I haven't seen this happening to anyone else on those apps since they get mostly positive reviews.

 

[B. Diddy]

Cheetah Mobile is regarded by many as a shady character that pushes useless "cleaner"-type apps that don't do anything to improve system performance, while sneaking in various forms of adware and unwanted functions. None of the AC Editors, Moderators, nor Ambassadors recommends their stuff. I've always wondered how legitimate a lot of those positive reviews on Google Play are.

 

[Luke Hedge]

Uh oh. I think it came back again. This time, instead of just the notification bar and bottom bar disappearing, the whole screen just blacks out with the same patterns I described before. It comes back on after a few seconds and then it goes to the state where the notification and bottom are gone and I can't do anything at all. Then after another few seemingly long seconds, it puts me to my lock screen and I can continue normally for the next few minutes. Sometimes, the screen blacks out and goes back to the no top or bottom bars state repeatedly every few seconds. And also, yet again, sometimes it changes my home screen background to default.

And I've pretty much at this point uninstalled all those CM apps but it still happens. And now, even when I am in safe mode, it still happens with the box that says "safe mode" being the only thing present at the bottom left of the blacked out screen.
But this does not occur as often anymore when I watch YouTube or when I am web browsing, but it still can occur every now and then. Right now, this mostly occurs when I am playing the Clash Royale game.

 

[B. Diddy]

Hmm, that's odd. You may need to try a factory reset. I'd normally suggest wiping the system cache partition, but LG phones don't let the user do that.

 

[Luke Hedge]

I tried factory resetting, and everything seemed to be going fine until I restarted the phone again. Now, it won't even take me to the login screen. I keep getting the screen you get when you first start up a phone after a factory reset but then after a few seconds, it goes to a black screen but only the top and bottom bars are showing and it just stays there. I tried to restart it multiple times, and it kept going back to that black screen. This never happened to me at all when I factory reset the same phone in the past.


I also tried restarting with safe mode, but the same thing happened. All that managed to do was get the "safe mode" box at the bottom left of the screen.
I tried calling that phone and it didn't even ring either.

Then I tried to factory reset again by powering off then doing the holding power and volume down buttons method, but it denied me because it was disabled by kill switch.

 

[B. Diddy]

It sounds like either a corrupt firmware or faulty hardware. The only thing I can think to do know is to reinstall the firmware, but I'm not sure if there's an easy way to do that on your phone. There used to be an LG Mobile Support Tool that could be used to reinstall firmware, but I'm not sure if it's available any more. Try checking the forums at XDA-Developers.com.

 

[Luke Hedge]

I was able to reset my device through google using Android Device Manager. But every time I restart or power off my phone and turn it back on, it goes to the same problem as before. The main reason why I restarted in the first place was because my home screen button and recent apps/multitasking buttons doesn't work, so I thought that restarting would help. The buttons did not work when I factory reset my phone for the first time ever, but I restarted the phone and it worked fine after that(until I ran into all those problems we discussed over the course of these few months). But until the last few days when I factory reset the phone again, these problems came up.

 

[B. Diddy]

If it's corrupt firmware, a factory reset wouldn't help, since the phone would still be using that same corrupt firmware.

 

[Luke Hedge]

After quite a while of troubleshooting, I think the problem might've been mcafee. Before, I pressed activate, but the last time I did it, I pressed activate later. This seemed to fix most of my issues. I haven't tried out if rebooting would still make the phone glitch out, but most things are working fine now. The only problem now is that I cannot download some of the apps in the google store because it says "Your device isn't compatible with this version" even after updating google play.
Edit: Nevermind. After coming back after a few hours, the apps I wanted to install became available and compatible. The only thing now is to see if powering on and off won't break and glitch the phone out.

 

[Luke Hedge]

Powering on an off does not break the phone. Everything is working fine except for the original problem. The black out problem still happens, even after all this trouble.....

 

[Luke Hedge]

I have a feeling that the problem I've been experiencing is caused by the screen protector, because for another phone, when a screen protector was installed, the phone would do a similar black screen and you couldn't do anything for a short while. But after removing it, it was fine again. I suspect that's the problem I've been experiencing, but for this phone, it blacks out when the phone is under some load.