This is a RCA rear projection TV model D52W26YX2 bugging me lot.
Came in with popped pincushion circuit and slightly narrow raster. Pincushion stuff which I duly fixed rather easily with OEM parts and checked things more throughly due to stripped and overtightened screws, loose wires not in their places. Soooo...
When I saw shoddy job on the old repair (same problem and other items) then I realized I have a "many unknowns" of questionable parts (is it correct parts?). Also I need to do PROPER geometry and setting up 3 CRTs centering and make them perfectly vertical & horizontal via yoke and centering rings. That required convergence be disabled. That when I saw the problem that I'm struggling with ever since.
Green CRT is most critical to everything so I focus on that one first, the problem is horizontal non-linearity raster scan with right side pulled short of bezel that I cannot correct, left is stretched, right side is bunched up and fall short of the bezel to overscan. Far as I can determine this affected both red and blue as well.
This is possible I got a unit with wrong board or wrong component (especially fly and linearity coil. This has happened ONCE with one unit (CTC169 few years ago and luckily have correct board!
Can this possible also caused by incorrect B+ for horizontal circuit?
and how much for normal function? Mine measured 137V and I forgot what it was for a working ITC222, the service manual for once failed to have the voltage for THAT! :o
Oh yeah, this unit had a fake part as part of old repair, horizontal transistor so I replaced it with OEM part and I thought would fix that, nooo.
Cheers, Wizard
Came in with popped pincushion circuit and slightly narrow raster. Pincushion stuff which I duly fixed rather easily with OEM parts and checked things more throughly due to stripped and overtightened screws, loose wires not in their places. Soooo...
When I saw shoddy job on the old repair (same problem and other items) then I realized I have a "many unknowns" of questionable parts (is it correct parts?). Also I need to do PROPER geometry and setting up 3 CRTs centering and make them perfectly vertical & horizontal via yoke and centering rings. That required convergence be disabled. That when I saw the problem that I'm struggling with ever since.
Green CRT is most critical to everything so I focus on that one first, the problem is horizontal non-linearity raster scan with right side pulled short of bezel that I cannot correct, left is stretched, right side is bunched up and fall short of the bezel to overscan. Far as I can determine this affected both red and blue as well.
This is possible I got a unit with wrong board or wrong component (especially fly and linearity coil. This has happened ONCE with one unit (CTC169 few years ago and luckily have correct board!
Can this possible also caused by incorrect B+ for horizontal circuit?
and how much for normal function? Mine measured 137V and I forgot what it was for a working ITC222, the service manual for once failed to have the voltage for THAT! :o
Oh yeah, this unit had a fake part as part of old repair, horizontal transistor so I replaced it with OEM part and I thought would fix that, nooo.
Cheers, Wizard
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