[lcaillo]

The most common symptom in a Hitachi would be shutdown, which is far more likely to be something else. High voltage that is off or focus problems can be other symptoms. Bad flybacks are rather rare in Hitachi sets, however.

You would likely get more useful information if you were to post your model and symptoms, along with any troubleshooting you have done and why you might be suspecting a bad flyback.

 

[lcaillo]

Is the drive to the flyback varying? B+ stable? If it is then you might have a bad flyback. My first thought would be a bad cap or a bad solder joint. When a flybak fails it is usually not intermittent like this, but it is possible.

If the center only is changing in focus then it is not likely a flyback problem, but a deflection or dynamic focus problem. The flyback would affect focus over the whole picture, typically.

 

[lcaillo]

Re: dynamic focus?

Sounds more like a cap if it is changing.

 

[lcaillo]

Re: dynamic focus?

There are too many possibilities in the power supply, dynaminc focus, and high voltage control. Some troubleshooting and study of the circuit designs would be needed to proceed.

Your threads were merged. Please do not start multiple threads to discuss the same problem.