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Vertical deflection timing cap
In a solid state b&w TV set is there a vertical timing capacitor that is not an electrolytic cap. If it does and the cap opens or shorts would that likely stop the horizontal deflection as well. This tv I’m working on has an ic chip that controls both I’m trying to determine if the ic is bad or a possible cap. It had vertical but was flickering in and out then both went dead.
Last edited by timmy; 04-01-2024 at 10:10 AM. |
#2
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Yes. A B&W will have an osc stage, one for Vert & one for Hoz.
there will also be hold controls. Many varieties so need more info & symptom to help if you need it. BTW Betters color sets @1975 ++ have a master osc for both V & H The master freq gets divided down or counted down so both can go out at the same time. Sylvania was first, called it a think chip & was on the GT-Matic line. Very stable, reliable & saved parts. Cant beat that ! 73 Zeno LFOD ! |
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Exactly, W/O further information, it's quite impossible to offer any guidance beyond wild speculation, it's true that many sets of the era did have linear ICs at the heart of the main board that did most of everything, W/O knowing the make, or MO#, or perhaps the IC# in question, it is kind of like flying blind.
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#4
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I don't think any TV was designed so that failure of the sync IC would stop the horizontal sweep from running (a sure way to burn up horizontal outputs and/or flybacks). The first IBM PC color monitor did that, resulting in a lot of failures when they were turned on without connecting to the video/sync output of the PC. TV designers laughed at that blunder. It is conceivable that some sets had a safety feature to prevent burning a line into the CRT if vertical failed, but I can't point to one myself.
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#5
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Quote:
Please Don't remind me of that horror! :O First job out of HS, Computer repair shop... I SAW IT!
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために |
Audiokarma |
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Here’s what I’m working on Sinclair mtv1 and the ic is not available or interchangeable found nothing online so I’m trying to rule out if the ic is bad or not. This is an electrostatic crt tv.
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#7
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This is a rough schematic of the deflection ic. Don’t know if this can be matched.
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#8
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Looks like it has a TI symbol on the IC.What are the numbers ?
You can also check the pins for the VCC ( B+). Probably 12 VDC. And see if it gets real hot or stays cold when on a while. BTW IIRC shango did one a few yrs ago. Zeno |
#9
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It uses 4.8v and staying on awhile it don’t get hot or warm.
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#10
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How could I find out if Shango did one I looked but there’s alot of his videos.
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Audiokarma |
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__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために |
#12
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#13
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https://www.guenthoer.de/doku/service-sinclairmtv1.pdf
From what it seems, the ICs are proprietary, and quite unobtainium, and aside from getting lucky and finding a bad cap/resistor or connection fault, chances of it working are very low.
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために |
#14
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#15
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From what I have seen, this unit has a very bad reputation of self destruction due to battery leakage and even perhaps bad caps, where the electrolyte has attacked and destroyed the connectors on and in between the boards, and possibly traces on the board, and interconnects between the top and bottom of the boards.
All should be inspected under a good microscope.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために |
Audiokarma |
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