Sony KV-36XBR450 HELP
You are not going to like what I am telling you.
The problem you are seeing is that the emission of the CRT has decreased to a point where there is not enough beam current, and the drive circuits are shutting down the beam bias to the electron-gun. The emission is at the borderline stage where it is on the edge and that is why it turns on and off. Most likely, as the cathode in the electron-gun warms up enough to reach a high enough emission, the bias circuits will switch on. Then when the emission drops just slightly because of the beam loading, there is a fault detected, and the bias circuits are switched off.
When you see the picture, the lack of sharpness (soft picture) is because there is too low a beam current for the electron beam to become narrow enough to be sharp at its focal point. There are circuits in the high voltage section to control focus, but they cannot go beyond what the beam cannot deliver.
The solution would be to change the CRT. This would not be feasible, and the CRT is no longer available. It will also be expensive to pay the labor to have the CRT changed. It would require a tech with the skills to perform the factory level purity set-up, convergence, pin-amp, scanning, and color temperature set-ups.
The labour alone could cost a minimum of a few hundred dollars. If I remember correctly, when the CRT was available for your model, it was costing over one thousand dollars. There are some strip magnets and rubber spacers that will also have to be replaced. Sometimes there may be some other small parts required. This will add to some extra cost.
In your case if the set is 6 years old, there is no gaurantee of how long it will take before there are other types of failures. Personaly I would not fix this set!
I would suggest to get yourself an LCD or Plasma HDTV to replace your set. Stay with a known brand name, and take the extended warranty. For myself, I would buy only a brand name that the company also manufactures broadcast and industrial TV equipment. This way, you know you will have original design, and high quality assembly in the set. You will get what you pay for.
In a very basic context, if you are going to watch in a dimly lighted room the Plasma is a good choice. If you are going to watch in a room that is lighted most of the time the LCD would be a better choice. Both systems are good. It depends on your preference and they way you will use the set.
on Jul 18, 2008