Answer to "What hardware is causing screen splitting issue on LG G4?"My display issues were bad enough that I was ready to replace the phone. It had always run hot but when the display went to half static and/or locking and jogging it was even hotter than usual. Installed a battery app and saw the battery temp was at 107-111 when the display was screwed up. When turned off for a while and cooled, the display was fine for a short while until the heat started to climb. Battery was a few years old but took a charge. In a last ditch effort to save the phone I replaced the battery with one in the $17 price range that was promoted as newly manufactured. Screen problem disappeared, along with the heat. Temp stays at 73-74 degrees now while streaming, playing Blitz and GPS.