On Jan 23, 3:47*am, "A.D." wrote:
Hello.

We have an old Sony Trinitron CRT TV, 72cm maybe 5 years old or more and
since some years a problem.
The problem is: The TV switches from itself between coloured screen and grey
screen, maybe every half an hour.

Does anyone has an idea what the problem is?
Maybe just a contact problem, but in which area?

Thx.

The set thinks that it is not receiving the color burst signal on the
back porch of the sync pulse. If that confuses you, then you must at
least give us the model number of the set, SONY make many sets.