My SONY Trinitron KV-35S40 ended up with the same problem.
We were watching the TV and picture+sound went off by itself.
After this, stand by timer indicator red light is flashing.
I looked up the manual, Troubleshooting section says
"Your TV may need service", "Call your local Sony Service center".
It is too heavy to carry, so will have to call them for service at home :-(
Sathya Ramanna, October 2005
