I've got a Samsung harmon/kardon that is unresponsive when turned on. The LED reads out "ON", then "Wifi", then "Wifi disconnected" for a bit before turning off. "BYE"
It does not respond to any commands from the remote or built in buttons besides the power button.
I've attempted to update firmware via USB to try and fix this but have had no luck - it just kept going through it's wifi disconnected routine. Used the 2019 Sound Bar Upgrade Guide from downloadcenter.samsung.com