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  #1  
Old 02-04-2015, 10:50 PM
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Arcanine Arcanine is offline
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Sony 5-303W Blank Screen

I've pretty much entirely recapped the board and this is all it still gives me.



it has a few less lines, but I don't get it. What is this particular issue? Bad transistor?
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Old 02-05-2015, 12:46 AM
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It looks like the Horizontal Frequency is way off. Does it have sound, can you see any movement at all on the screen?
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Old 02-05-2015, 08:50 AM
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Wires on mine are very brittle - perhaps you broke a wire or two? Check the voltages around the horizontal oscillator and you'll likely find a problem. Crisp looking picture, just need to pull the oscillator in to sync.

Cheers,
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Old 02-05-2015, 09:28 AM
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Quote:
Originally Posted by Eric H View Post
It looks like the Horizontal Frequency is way off. Does it have sound, can you see any movement at all on the screen?
Yes. It has sound and reception. I can faintly see static on empty channels. When I tune to my transmitter I get perfect sound but no movement otherwise.

Perhaps the 2SC41 transistor is bad? It does get fairly warm.
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Old 02-05-2015, 01:24 PM
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zeno zeno is offline
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Going with hoz freq off is there a sub hold on the PCB ?
If so may have bad spot.
If the 2SC41 is the hoz out it may be cause the freq is off.
Transistors almost always work or not so I dont think
thats it. In any case dont run it long if its hot or it
will short.

73 Zeno
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Old 02-05-2015, 03:14 PM
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Eric H Eric H is offline
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I noticed on my set it has some adjustments (four pots) right above the speaker, probably Vert height and lin but maybe one of them is the Sub Horiz adjustment?
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Old 02-05-2015, 04:19 PM
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Quote:
Originally Posted by Eric H View Post
I noticed on my set it has some adjustments (four pots) right above the speaker, probably Vert height and lin but maybe one of them is the Sub Horiz adjustment?
I'm not sure. I replaced a blown vert. driver transistor today on one of my sets and it brought vertical totally back. I'm going to tackle this set now. I was angry when it died.

Lucky for me chesters has all these transistors in stock.
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Old 02-05-2015, 04:51 PM
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Quote:
Originally Posted by Eric H View Post
I noticed on my set it has some adjustments (four pots) right above the speaker, probably Vert height and lin but maybe one of them is the Sub Horiz adjustment?
Yep! fourth hole from the rear. From rear; Focus, Vert Height, Vert Linearity, Horizontal Frequency and Vertical Output Bias (covered).

jr
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Old 02-05-2015, 05:09 PM
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Quote:
Originally Posted by jr_tech View Post
Yep! fourth hole from the rear. From rear; Focus, Vert Height, Vert Linearity, Horizontal Frequency and Vertical Output Bias (covered).

jr
I finished recapping the board and it still has the same symptom. I also changed the Horz. Driver transistor, same thing. either the actual output is bad, but that I doubt as it's still getting warm.

I'm thinking the bias transistor it self is bad.
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  #10  
Old 02-05-2015, 05:35 PM
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Does tweeking the Horizontal Frequency pot have *any* effect at all on the number or angle of those bright horizontal lines? have you tried cleaning the pot?

jr
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Old 02-05-2015, 06:29 PM
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Quote:
Originally Posted by jr_tech View Post
Does tweeking the Horizontal Frequency pot have *any* effect at all on the number or angle of those bright horizontal lines? have you tried cleaning the pot?

jr
It shifts them around a little, but it has almost no effect on them at all.
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Old 02-05-2015, 07:05 PM
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It shifts them around a little, but it has almost no effect on them at all.
Hmmmm..... I'm stumped, mine seems to have a profound effect on horizontal frequency, to the the extent of almost killing the horizontal oscillation (squigging) when turned fully clockwise.

jr
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  #13  
Old 02-05-2015, 10:57 PM
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Quote:
Originally Posted by jr_tech View Post
Hmmmm..... I'm stumped, mine seems to have a profound effect on horizontal frequency, to the the extent of almost killing the horizontal oscillation (squigging) when turned fully clockwise.

jr
Adjusting the horz. frequency alters the screen size a little and makes the lines move around, not much else.

Turning the horz. on the front of the set moves the lines around a little.

I'm at a bit of a loss.
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  #14  
Old 02-06-2015, 01:19 AM
EdKozk2 EdKozk2 is offline
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Did you try adjusting L15, the horizontal stabilizer transformer coil? It looks like a square transistor radio IF coil. It's mounted on the Sweep circuit board, center left
viewed from the component side.
Ed
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  #15  
Old 02-06-2015, 08:08 AM
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I see you have it tuned to channel 13. Have you tried the set with a digital converter on channel 3 or 4?
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