Hi! My name is Ameen and I'll be assisting you. Secure Remote Assistance is NOT REQUIRED (But Helpful)
I am sorry you are having this concern, I will do my best to help you today.
To answer your question -> See steps below:
A couple of things you can try
1 - Unplug TV power cord from the wall, and disconnect all other devices connected to your TV except aerial cable, and turn TV on again.
2 - If step 1 fails, ensure you are using the latest firmware.
3 - If step 2 fails, perform a factory reset.
4 - If step 3 fails, it probably indicates a hardware failure on the TV, go through Sony Support to get your TV repaired.
Let me know if you have any follow up questions. I am here to help you.