#1
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Zenith Z1920W
So, my Zenith works great but has these lines on the top of the screen. What is causing it?
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#2
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I don't remember the value; but, there is a capacitor in the vertical circuit that is failing (probably something between a 47uf and 220uf). How old is this set and what main module does it use?
You really need to address this before using the set because that failing capacitor will likely cause other parts to fail. On newer sets with a vertical output IC, it will eventually cause the IC to fail.
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http://www.youtube.com/user/radiotvphononut |
#3
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Quote:
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#4
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I have a 1976 Sanyo set that has deveolped that problem.. The pic gets real bright, and when you turn down the brightness the color looks weird and you see the retrace lines at the top even more.. Looks like it could be too much HV or something..
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Looking for an all tube or hybrid color TV set from the late 1960s, early 1970s that's in a steal cabinet.. |
#5
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Sanyo had a problem with the resistors on the CRT board changing value.
Unsolder one end of the chain and check, on the screen grid of the CRT. rrrhre2s |
Audiokarma |
#6
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My money is on the filter cap for the 200 V feeding the video outs.
It happens to every brand set. Its usually a 4.7 mfd. To find it go to CRT SKT. There are 3 transistors each with an about 18K ohm 2W resistor feeding the collectors. Where the resistors join is the 200 V. The cap is off that point sometimes on the CRT SKT or usually the main board near the FBT. Just follow the wires. There may also be a coil in series. Some sets dont have a board at the CRT SKT, everythings on the main PCB. 73 Zeno |
#7
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9-181 set & yes change all the 'lytics in the V out. Also look
under the big filter cap for mung leaking out. Finally check the yoke plug on the HV module for overheating at connector & on the PCB. That should keep it running another 30 + yrs. 73 Zeno |
#8
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These lines are on the on top two inches or so of the screen.
Thank you everyone for the input. |
#9
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Tim, Is that the hospital set you got from me? I never opened it, so the caps are it
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"When resistors increase in value, they're worthless" -Dave G |
#10
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No Dave, whole different set.
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Audiokarma |
#11
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While you're in there, change the electrolytic capacitor on the start-up board (the little board that's mounted on the horizontal output heatsink. This capacitor won't cause your problem; but, it will cause a "dead set" and it's a common failure.
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http://www.youtube.com/user/radiotvphononut |
#12
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Thank you. We will do that.
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