G4 battery stuck at 80%, won't connect to mobile data.

[mattl2]

Last night I went to a movie and turned off my LG G4; when I turned it back on later the fist thing I noticed was that the battery was at 80%. It was at about 40% when I turned it off. Second thing I noticed is that it wouldn't connect to 4G. Calls and texts worked though. I rebooted the phone several times and even swapped the battery and took out and put back in the sim card. Nothing. After about 10 reboots (based on internet suggestions I found) I had 20-something% battery and 4G! I rebooted a few more times (as a test) and it still worked. Then I left it off for half an hour, and afterwards it had 80% battery and no 4G! The only way I've found to fix it is to just keep rebooting over and over again, and the trigger to break it seems to be to leave it off for more than 10 minutes. I go to the movies a lot so please don't suggest I just don't turn it off that long. I've seen a few others online with a similar problem but no definitive solutions. Also, my phone got wet several months ago, and the sensors inside turned red. This has never affected the phone but I mention it because I'm not sure I'll still have a warranty.

Edit: Forgot to mention I performed a full factory reset. Didn't change anything.
Edit 2: After a lot of tinkering, it seems that plugging it into a charger while it's off makes it more likely to work properly when turned on. Weird!

 

[B. Diddy]

It may very well be due to the prior water damage. The results of water exposure sometimes don't show up for a few weeks to months, because it may take that long for a particular circuit or component to corrode enough to start causing issues.

 

[mattl2]

Perhaps. But I've found other cases through Google (very few) of other G4 users who have experienced the same problem - 80% battery and no data. And they didn't mention their phones ever getting wet.

 

[B. Diddy]

Interesting. Did those users assert clearly that the phone was never wet, or was it never mentioned? People don't always volunteer (or remember) that information. There have been several times on the forums when I've engaged someone in a discussion about something glitchy, and maybe 10 responses down, it comes out that the phone got dunked in a pool a few weeks ago.

 

[mattl2]

No, it just wasn't mentioned. So maybe that's a potential problem after water exposure. Oddly, my phone hasn't been experiencing that problem for a day or so and now has a new boot problem... Upon boot it often says it's installing a firmware update that it never downloaded, and never progresses past 0%. It also says not to unplug the USB cable which was never plugged in to begin with... The power button won't shut it off. I have to remove the battery (this is the EXACT reason I buy phones with removable batteries.) Anyways I'll probably end up starting a new thread for this problem.

 

[B. Diddy]

I wonder if it's related at all to the bootloop issue that LG finally recognized: LG admits G4 bootloop problem is a hardware fault, will repair affected devices - Android Authority

 

[mattl2]

I wonder if it's related at all to the bootloop issue that LG finally recognized: LG admits G4 bootloop problem is a hardware fault, will repair affected devices - Android Authority

That doesn't really seem to be the problem I'm having, but as you said maybe it's related. An update, it actually IS still having the problem where it boots up to an 80% battery and no data connection - most of the time. Or sometimes it boots to the firmware update screen that never progresses past 0% and the battery has to be removed. OR if I'm really lucky it'll boot normally. And as I said, plugging it into the charger while charging helps it boot properly. I'm finding this problem mentioned more and more online and one promises his phone never got wet. I guess I should just go to a Verizon store.