I'm very sorry to hear that has happened, and I apologize for any inconvenience this may have caused you. In order for me to help you most accurately, please provide for us the complete model code for this device.
My new 55" top of the range smart tv takes an age to turn on.It clicks and then seems to turn off turn on and off a few times and sometimes will turn on with the smart button and then i can turn tv on.
It also seems to work if i reset my sky wireless router (upstairs) and occasionally turns itself off.
Is this an internet connection problem or a firmware issue.Please help !!!!!!