KDL-55W800C. Didn't do firmware update before. However, when problem started I tried to reflash using USB but it didn't work coz tv keeps rebooting. Guess tv is a goner now.
What is the TV model? This is a common problem for most Sony android models.
If you have done a firmware update recently, rebooting is a common error. Sony does not seem to honor any repairs due to software glitches like this. Need to reflash the original firmware or to factory settings.