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Old 05-21-2018, 10:47 PM
kramden66 kramden66 is offline
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Zenith TV Vertical issue Chassis 16K20

The set is recapped the issue is you can make the image fill out but its stretched through the picture and crushed at the top and bottom , if you letter box the image using height and lin you can make the middle look better or closer to a circle but it still crushes at the top and bottom.
tried replacing the component combos it changed nothing , painfully removed the yoke and checked resistors they are ok , tried another vert tube nothing.
any ideas ?
could the 100mfd cause this if it was defective ?
see pics below
mike
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File Type: jpg zenith vertical issue.jpg (73.6 KB, 14 views)
File Type: jpg vertical closeup.jpg (69.0 KB, 15 views)

Last edited by kramden66; 05-21-2018 at 10:51 PM.
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Old 05-21-2018, 11:01 PM
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Electronic M Electronic M is offline
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Typically the 100uF makes the bottom pull up and inhibits correct linearity...Which may have morphed into what you have with control adjustments to try and correct for it...

Also, bear in mind that if there is less or more horizontal overscan than vertical overscan then it will not be round even if the vertical is working perfectly and perfectly linear. Zeniths have a copper width sleave that you can slip between the yoke and CRT neck...It will affect both axes some but has a MUCH greater effect on the horizontal. Once the vert is perfectly linear increase horizontal overscan using the sleave until circles are round.
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Old 05-21-2018, 11:55 PM
kramden66 kramden66 is offline
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Yes I know about the sleve and if pushed in gaps appear on the sides.
I'm going to check when I can that 100uf , after posting this and looking at the schematic again it hit me that the electrolytic I put in could be defective.
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Old 05-27-2018, 01:46 AM
kramden66 kramden66 is offline
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Well it was the 100uf that was bad but now I have a couple others issues that I will start a new thread on.
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