I was able to get my defective phone to boot by freezing it for about 15 minutes in large freezer, and letting it run inside the freezer. I have heard of people being able to recover data by freezing the batteries and one person suggested to run your phone in the freezer. I tried it and it worked.
Before I tried the freezer method I was only able to get to the Android is Upgrading screen maybe 10 times out of over 100 boot loops. The farthest I ever got on that screen was 8 out of 101 apps. With the freezer method it fully booted on the first try.
First I froze the battery alone for maybe 20 minutes. Then I placed the battery in the phone and tried booting into recovery. It didn't work. So I removed the battery, put it back in and and let both of them sit together for about 15 minutes in the freezer. Then I returned and the phone fully booted on the first try. I tried booting into recovery from Nandroid Manager but that just reset the phone. Since it seemed stable and I wanted to keep the phone as cold as possible I just used My Backup Pro and Titanium Backup to back everything up.
I honestly gave up and I am sending my phone to LG today, so this was literally my last resort. Hope this helps someone.