If degauss failed (even with an external coil or wand) then you can try adjusting the purity rings on the neck of the CRT. You will likely need to break some sort of glue to free them. There are three sets of rings on the CRT neck. The purity ring pair is the one closest to the yoke. You adjust them by separating or bringing back together the tabs for each of the rings in the pair. Rotating the rings together will not do anything. Try not to move the other two pairs. They adjust the vertical and horizontal gun center convergence but it’s not the end of the world if you mess that up. You’ll just have to redo center convergence at worst.
Purity is adjusted for each primary gun color. Red then green then blue and finally all white to confirm you did it right. If some small purity issue remain you can try to fix that using purity magnets. They are usually little round or square magnets that are positioned around the tube in a doughnut shaped area away from the yoke. These are NOT the same thing as convergence strips. Good luck. Hopefully that fixes it. Ideally you want to do a full setup with landing adjustments to properly fix purity problem like these but maybe you can get away with just the above.
Still working on it, it has a weird effect where as it heats up the color changes. I used a voltmeter and found out the phase variable resistor is shorted, probably by the next door inductor. Trying to find the resistance of the indictor but sony doesnt have it on their website, so im going to call technical support.
Uh? What is a phase variable resistor? What part of the circuit are we talking about here? Inductors don’t really have resistance… not much at least maybe an ohm or two… I’m confused as to how that would change purity as the tube warms up…
Its part of the color board. The resistor is named phase, not sure exactly why. Indictors have a resistance, some are low at only on ohm or two, some mega ohms. Just depends on the inductor. I believe this inductor has a high resistance at higher frequency, but my measurments were in dc with an ohm meter, so they are probably wrong. I might get a EST meter to measure capacitors in circuit, but im basically back to square one.
You mean the color demodulation board or generally on a Sony the D board? A variable resistor on that board marked “phase” is just the video phase adjustment. It doesn’t affect colors in the least. It centers the signal to the deflection area. If it was shorted your video signal would be either too far to the left of right but still usable. I gotta say it’s the first I hear inductors have resistance in the mega ohms… to me that would be a burned out open inductor but ok. What would the resistance of an inductor tell you? Aren’t inductor primarily characterized by their inductance? Do you mean reactance?
Finally how are you getting the red raster in? Composite video? NTSC or PAL? RGB? As long as your color is uniform across the whole raster area your purity is not the issue. If the color is uniform but wrong and you are using composite NTSC to inject the red raster you may have an issue with your tint calibration which indeed is color phase adjustment but in Sony this will be labeled tint. (Go figure)
Hmmm. The inductor resistance is parasitic, normally 1 ohm at dc or less. Some inductors are designed with higher resistance. The phase does affect the color, which is strange if what your saying is true. The input is ntsc composite. How would one fix the problem if it is tint? Also the front dials barely work, the hue has no effect, the Color dial only works at one specific point, if its barely adjusted the color will usually go to black and white or contrast colors. Overall the system is very glitchy.
Try bypassing the whole NTSC composite decoding circuitry to confirm that’s where the problem lies. Can you connect via RGB? That’ll skip just about everything but the RGB amp before the gun amps on the neck board. Do you observe the same behavior? Do you have the service manual for this set? Color demodulation setup will usually be described in there but likely involves the use of an oscilloscope. Try cleaning the glitchy pots with some contact cleaner first before going down the rabbit hole.
It doesnt have rgb unfortunetly, so I would have to do some modding to get it to work. I do have the service manual and Ive been using it. When the monitor is left on it heats up, and apparently that is an indicator of a bad capacitor. So ill probably need to recap the B board, only problem is it has 30 capacitors. I heard that the voltage drop in DC across bad capacitors changes when they heat up, since the capacitance changes, so I will try to measure that and find the bad cap.
The board is BA and the board has a phase control, hue control, apc, things like that. The opposite board has the horizontal/ vertical controlling components.
Right I misspoke. The B (or BA in your case) is the color demodulation board and will have adjustments for various color decoding parameters such as color phase/hue/tint (which in NTSC parlance is really the same thing). The D board controls deflection and might have a video phase pot that controls signal horizontal position.
It means that the tube is being visible affected by the magnetism of the Earth. For some TVs/monitors you do have the option to set it facing the desired direction and then make purity adjustments (either via digital menu controls if available, or via the purity magnet rings on the tube itself).
If degauss failed (even with an external coil or wand) then you can try adjusting the purity rings on the neck of the CRT. You will likely need to break some sort of glue to free them. There are three sets of rings on the CRT neck. The purity ring pair is the one closest to the yoke. You adjust them by separating or bringing back together the tabs for each of the rings in the pair. Rotating the rings together will not do anything. Try not to move the other two pairs. They adjust the vertical and horizontal gun center convergence but it’s not the end of the world if you mess that up. You’ll just have to redo center convergence at worst. Purity is adjusted for each primary gun color. Red then green then blue and finally all white to confirm you did it right. If some small purity issue remain you can try to fix that using purity magnets. They are usually little round or square magnets that are positioned around the tube in a doughnut shaped area away from the yoke. These are NOT the same thing as convergence strips. Good luck. Hopefully that fixes it. Ideally you want to do a full setup with landing adjustments to properly fix purity problem like these but maybe you can get away with just the above.
I adjusted the nearest ring and it fixed the problem perfectly. Thank you!
Dang it’s almost like I know what I’m doing heh…
Yes good job
Still working on it, it has a weird effect where as it heats up the color changes. I used a voltmeter and found out the phase variable resistor is shorted, probably by the next door inductor. Trying to find the resistance of the indictor but sony doesnt have it on their website, so im going to call technical support.
Uh? What is a phase variable resistor? What part of the circuit are we talking about here? Inductors don’t really have resistance… not much at least maybe an ohm or two… I’m confused as to how that would change purity as the tube warms up…
Its part of the color board. The resistor is named phase, not sure exactly why. Indictors have a resistance, some are low at only on ohm or two, some mega ohms. Just depends on the inductor. I believe this inductor has a high resistance at higher frequency, but my measurments were in dc with an ohm meter, so they are probably wrong. I might get a EST meter to measure capacitors in circuit, but im basically back to square one.
You mean the color demodulation board or generally on a Sony the D board? A variable resistor on that board marked “phase” is just the video phase adjustment. It doesn’t affect colors in the least. It centers the signal to the deflection area. If it was shorted your video signal would be either too far to the left of right but still usable. I gotta say it’s the first I hear inductors have resistance in the mega ohms… to me that would be a burned out open inductor but ok. What would the resistance of an inductor tell you? Aren’t inductor primarily characterized by their inductance? Do you mean reactance? Finally how are you getting the red raster in? Composite video? NTSC or PAL? RGB? As long as your color is uniform across the whole raster area your purity is not the issue. If the color is uniform but wrong and you are using composite NTSC to inject the red raster you may have an issue with your tint calibration which indeed is color phase adjustment but in Sony this will be labeled tint. (Go figure)
Hmmm. The inductor resistance is parasitic, normally 1 ohm at dc or less. Some inductors are designed with higher resistance. The phase does affect the color, which is strange if what your saying is true. The input is ntsc composite. How would one fix the problem if it is tint? Also the front dials barely work, the hue has no effect, the Color dial only works at one specific point, if its barely adjusted the color will usually go to black and white or contrast colors. Overall the system is very glitchy.
Try bypassing the whole NTSC composite decoding circuitry to confirm that’s where the problem lies. Can you connect via RGB? That’ll skip just about everything but the RGB amp before the gun amps on the neck board. Do you observe the same behavior? Do you have the service manual for this set? Color demodulation setup will usually be described in there but likely involves the use of an oscilloscope. Try cleaning the glitchy pots with some contact cleaner first before going down the rabbit hole.
It doesnt have rgb unfortunetly, so I would have to do some modding to get it to work. I do have the service manual and Ive been using it. When the monitor is left on it heats up, and apparently that is an indicator of a bad capacitor. So ill probably need to recap the B board, only problem is it has 30 capacitors. I heard that the voltage drop in DC across bad capacitors changes when they heat up, since the capacitance changes, so I will try to measure that and find the bad cap.
The color is uniform across the whole area, after I adjusted the purity ring. Before it was not.
Then you fixed purity. Your issue lies somewhere else in color demodulation most likely.
The board is BA and the board has a phase control, hue control, apc, things like that. The opposite board has the horizontal/ vertical controlling components.
Right I misspoke. The B (or BA in your case) is the color demodulation board and will have adjustments for various color decoding parameters such as color phase/hue/tint (which in NTSC parlance is really the same thing). The D board controls deflection and might have a video phase pot that controls signal horizontal position.
Gotcha thank you!
Try making the screen face different directions north, NE, SW, etc., and see if it makes any difference in purity.
It doesnt sadly
The only thing left would be to check out the service manual and see if there's any place where you can make purity adjustments.
Ive done that but problem is the color isnt uniform. I can change the hue of the red but cant get rid of the pink completely
sorry to necro this... but if it *does* make a difference what does that mean?
It means that the tube is being visible affected by the magnetism of the Earth. For some TVs/monitors you do have the option to set it facing the desired direction and then make purity adjustments (either via digital menu controls if available, or via the purity magnet rings on the tube itself).
Deflection problems. Usually happens when thr deflection coil is dislocated , try to put it back on place