LG G3 Blue Screen

It is a hardware problem. The processor is unpacked. You have to heat up the motherboard , but is a temporary solution. After a time the phone will do the same problem.

Sounds to be software although you cannot rule out hardware issue completely. First, you should try to factory reset the device. While off, god the power button and volume down button. When the LG logo appears, release and then re-hold the power button while always still holding the volume down button. The factory set menu will appear and you can attempt to reset the device. This should fix all you problems.

Oven at 180º for 10 minutes works like a charm :D

Is it the heat or the dehumidifying that helps?

Had the same thing happen to me (actually bought dead phone on purpose but whatever) so I did this, as I didn't want to use owen (my parents probably wouldn't let me anyway): I took my hairdryer (2500 W), put extension that makes air more focused and precise, took the board out and blazed the SoC for few minutes. Note that I held SoC down all the time. So it worked and i placed paper between screen and SoC, thick enough to keep SoC pressed and possibly enchance colling a bit (as G3 doesn't have any cooling and thats such and failure but whatever). I hope it doesn't die again but I am confident it won't.