I have a 2015  KDL43W809C, bought in 2016 and out of warranty. It's been working fine, until yesterday, when it started behaving strangely.

Symptoms are that it will be displaying TV and then jumps into the Home screen. After a bit, the display blanks. Sometimes, the TV then reboots, other times it just sits there with a blank screen. Pressing Action Menu works, but nothing else.

I've tried Factory Reset, but it fails (my google account is still there). 1st Time Setup causes an immediate reboot.

The TV is running PKG5.381.0167EUA and has no apps installed.