Sony flybacks and high voltage transformers...

[DerekWilson]

Ok, so maybe I'm cheating since this is a problem I am having ... But I do think it is highly technical ... we'll see what the mods think ;-)

I am failry certain I have a problem with the flyback in my monitor. The problem is that the thing keeps going totally unfocused after it about 5 minutes of use. I guess it could be something else like a transistor somewhere getting too hot... But there have been a lot of reported problems with sony's flybacks on the model I am using (GDM F500).

So here's the highly technical question: how can I build or rebuild a flyback?

I am just finishing up degrees in electrical engineering and computer engineering at NCState University, so I am familiar with circuit design in a good number of forms. I've never actually worked with HV stuff, with the most powerful thing I've ever worked on being an audio amplifier. I have read a lot on safety though ;-)

If I need access to special equipment or tools to do such a thing, point me in the right direction. I've had people in other forums tell me that I can't build or rebuild one, but someone is obviously able to do it or we would have no monitors...

Any information would be most appreciated.

 

[Geniere]

It seems most of your flyback circuity is OK since you have deflection and brightness. There should be a resistor divider to derive a lower focus voltage. Maybe a resistor is cooked or has a cold solder joint to ckt board from years of heating. Seems latter is more likely.

Not my line of work though.

Regards

 

[IGBT]

Check the focus rectifier/diode assy. Might be bad.

 

[NeoPTLD]

Don't be so quick to jump to conclusion. You're better off buying a genuine replacement flyback if it is indeed the problem. Forget about rebuilding it. It is potted in epoxy and there is no way you can get to it. You can not build one unless you can find out the exact specifications(numbers of turns of each coil, wire size, core geometry, core material) for the flyback and wind it yourself. Again, not realistic unless you have the material. The core is most likely custom manufactured and the only way you can get one is buy a whole new flyback or buy in pallet load from OEM source.