LG G3 (d852), no OS, not loading into TWRP
Looks more like corrupted OS than no OS; try to boot into recovery by 1: remove battery 2: put battery back in, and power up by pressing both power button and vol up button 3: when you see LG logo release the buttons and immediately press them again to boot into recovery 4: perform a factory reset to clear corrupted files. 5: reboot.