A friend of mine that I recently helped had the issue with the phone stuck in a boot loop. He got the device swapped out back in December. We then saw this: http://www.androidauthority.com/lg-admits-g4-bootloop-problem-hardware-fault-669603/
The replacement device was flashing Wi-Fi signal. We booted in safe mode and did a factory reset and the phone was still doing the same thing. He tired the software repair assistant and even after that he still had the issue. He tried using the phone before restoring from the backup on the memory card after the factory reset. He ended up getting the phone swapped out a second time and has had absolutely no issues now. Way better battery life, hasn't changed any apps or settings, and is very happy. Hopefully some of you are still in warranty to get it swapped out. Good luck!
I fixed my loop issue and got all my data transferred. I tried to post the steps here but it didnt get approved so if anyone wants it, message me. Its really not hard to do.
Hi I've been searching the Internet on how to fix my g4 that is stuck in boot loop. Your post is the most luck I've had to hopefully fix my phone. I would be forever grateful if you would explain what you did to fix yours.. Thank you!!
Either put it in the freezer for a decent period of time (2 hrs, more if possible), not the phone while it's still in the freezer, hurry hurry and get that data backed up. Other solution I've come across, well, just PM me because it requires an oven.