SamyGO

Greetings to all good people here!

Long story short - after playing with region settings in service menu trying to activate tv sources other than aerial antenna, the TV doesn't look healthy anymore. It shows Smart TV screen first, blinks red light 5 times, shows a menu when the button on the rear is used... Long press 'Exit' button doesn't do any good. So I wonder if there's a way to hard reset the TV (eeprom, force fw upgrade, etc) or I need to go to service center?

TV model - UA55JU6400
fw version - 15.30

While this topic was waiting to be approved I did some further investigations and identified the eeprom chip. So I tried to perform hard reset. First I tried shortcut SDA+GND, after ~30-40 display backlit switches on but there's nothing on display. I removed the shortcut, switched off the TV with RC and used service menu sequence to turn it on. No effect. Then I tried SDA+SLC with same results, then SDA+VCC, SLC+GND and SLC+VCC. All combinations are with the same result. In the end the TV turns on with smart tv logo and black screen after that