My brother ended up buying a new phone when the problem happened in 2017. However, the broken LG G4 had been sitting on his shelf for over two years, and we decided it would be fun to back up all the stuff he didn't get a chance to recover (don't follow his example in not backing up your files!).
After a bit of Googling, I found that there was no cure for this problem - LG could replace the broken part, but that would wipe out all your data. Various users complained about this problem on forums and social media, and the general consensus was that there were two ways you might be able to temporarily revive the phone (at least long enough to do a backup): fire and ice. You could expose the phone to high temperatures or stick in the freezer.
Before we go any farther, I'd like to warn you that you should be very, very careful in exposing a phone (or any electronics, especially those containing batteries) to extreme temperatures, or using microwaves or ovens used for preparing food to heat up electronics - this can release all kinds of interesting harmful substances.
I started by sticking the phone in the freezer. I removed the battery, loosely wrapped the phone in a towel, and stuck the phone in the freezer for an hour. Then I re-inserted the battery and tried to turn it on. After a few attempts, the phone turned on for a few seconds. However, it quickly died again.
Realizing the freezer trick was probably futile, I tried Plan B: exposing the phone to high temperatures. I decided to start by using a heating pad - the kind you might use to soothe a sore muscle. I knew the heating pad would generate heat but probably wouldn't make things dangerously hot. After removing the battery, I wrapped the phone in a heating pad and switched it to its highest temperature. After about 20 minutes, I removed the phone and tried to turn it on. It took a couple of tries. I had almost given up, but I decided to keep the phone on the bootloop screen while it was wrapped in the heating pad.
A few minutes later, I heard a loud notification sound and saw the T-Mobile logo appear - a very good sign. I was able to connect the phone to my laptop using a USB cable and copy all of the stuff we wanted - photos, audio, and other original content. The phone stayed alive for a couple of days before perishing again.
The moral of the story?
- Back up your stuff regularly
- If you manufacture phones, try not to make dud products
- If stuff breaks, don't be afraid to Google around and try creative solutions (but don't do anything stupid or dangerous, and talk to a pro person if you're dealing with very important data)
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Edited by: Bibby, Nov 24th, 2019 @ 1:21 pm