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Old 02-05-2025, 09:39 PM
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Username1 Username1 is offline
Not sure how I got here.
 
Join Date: Dec 2009
Location: Orange County NY
Posts: 3,649
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Ok, so I been thinking about this goofy power supply part of the day, and I think that
if R186C was open, it would really mess up the chassis ground potential, and make
readings off for each source. Or C224B Is Shorted (Unlikely). So I think the best
way to figure out where the open resistor is, is to put the (-) volt meter probe
on the green wire of the focus coil and move the (+) probe along each of
the resistors towards the 275V source till you start reading high positive
voltages, then you will find the open resistor when you hit a big positive
jump..... So between R185A and R186A I think you should read about
+82V if the set is working... Just re-adjust your brain to think of the
-100V source as 0V with the (-) meter probe on it for reference.
I have not worked on this model before, But my thinking is that
with the point between R186C, & R240 making the ground
point, or 0V potential, then using that point as a reference
would make all readings off, if one of those resistors
is open....

And with your (-) probe on the red-yellow wire (Center Tap)
of the power transformer, know that your 275V Source
will read closer to 375V and be OK.


Just my thoughts on this one...

.
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Last edited by Username1; 02-06-2025 at 06:51 AM.
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