Re: WG 19v2000 flyback sub?

If you get oscillation, but nothing out of the flyback (actually a HV
transformer, as a flyback needs a yoke winding for it's operation-but
that's another group (Rasterlist))) then I would take a close look at the
driver transistor first, and it's connector.

On the other hand, I have had those HV transformers that had loose winding
assembly and the wires leading from the coil break at the solder terminals.
You might be able to re-solder them if you bend the broken one out
carefully, burn off the insulation, then add a tiny extension wire. I've
managed to fix a couple that way. Oh, and then wedge in silicon glue to
freeze the coil windings. Other folks might want to check this on their B&W
vector HV transformers to make sure theirs aren't loose and do some
preventative maintenance.

John :-#)#

At 08:33 PM 12/2/00, Robert Bayes wrote:
>Thanks, John, for your quick response.
>
>
>
> >Are you sure the transformer is open?
>
>As best I can tell. HV circuits are not my strong suit. I measure approx.
>10Mohms (depending on the humidity down here in Houston) with the HV diode
>*out* of circuit. Should I see this *high* a reading?
>
>
>A common failure on these is a bad HV
> >diode...
>
>I bought one of those just in case.
>
>do you get the screen voltage (400V) and the 90V output from the HV
> >unit?
>
>I get *no* screen voltage (~0.0V), *no* focus voltage (~0.0V) and only about
>10V (should be ~95V) for the spot killer circuitry. I am mindful of the
>characteristic hi-z of the circuit but it shouldn't yield *that* much of an
>error through my DVM! Please correct me if I'm wrong.
>
>The HO circuit _is_ oscillating though. The feedback must be coupling
>through the transformer core.
>
>If so, then the unit is almost running...likely a bad diode at that
> >point...there has been discussion here about sources for those diodes...I
> >use ones from old B&W TV's...
> >
>
>
>Lord knows, I hope you're right. However, so far, it seems to point to the
>flyback.
>
>What do you think, given this *new* information? Any suggestions?
>
>Sincerely,
>
>Robert
>
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Received on Sat Dec 2 14:16:44 2000