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Discussion Starter #1
Hi all,
Very informative, very intelligent group that is assembled here! I hope that I can add to the knowledge with equipment that I'm more familiar with than this one. I'm resurrecting a 51" rptv that I think I would like to manually converge before doing the electrical convergence. Here is the question...I need to know which of the three rings on each of the three crt's to adjust. In standard color sets, those would be purity rings, but this is my first time inside a projection tv and I am ignorant about how to align the crt's for convergence. Can someone guide me on this? I have scoured the SM and the user instructions but I don't have any detail about the yoke assembly. Thanks!
 

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I assume you are talking about the magnet assembly between the yoke and the crt board. I am not certain about your set specifically, but the rings are used to shape the beam and you will find that one set usually centers the spot, one set shapes it.

The set of rings on the yoke are used to position the image and should not need to be adjusted in most cases.
 

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Discussion Starter #3
Thanks, I was hoping you'd answer. I want to make the convergence the best I can. They used to say my tv's looked almost 3d when I got done with them in the shop, years ago...
Anyway, I have put up an X of thread running from corner to corner of the screen so I can locate the center. Shouldn't I do a static convergence with the magnet structure on the yokes prior to doing the electrical convergence in the menus? I have had to change the convergence ICs and a couple of open resistors, and I don't know what the guy before me did, but he was not a 'tech'. He was a DIYer and he failed, which is why I got the set.
Should I just go to the customer menus and converge as best as I can?
I know how hard it is to advise without being there, because I have done it for years. But now the shoe is on the proverbial other foot and if I can give more info, please let me know what you need.
Meanwhile, I hope the parts get here today (ICs)...Thanks again...:T
 

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What you want to do is zero the static convergence adjustment, then center it with the yokes. Then you can do the multi-point convergence.
 

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Discussion Starter #5
OK, I understand that, but there are several rings on each yoke. I need to understand what they do. Are all 4 rings for centering?
I have the set working beautifully right now. If it were you, and only if it were you, would you correct static convergence that's about 1/2" off diagonally? In other words, I put white thread from corner to corner on the screen, and put up the green X. It is off a bit, and I have converged the blue and red to agree with it. I've go a great picture, but won't it be better for my convergence amplifiers to set it up with the yoke rings and then go through the multipoint again? Or am I spinning my wheels?
Thanks for your help/patience!
-Dave
 

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The deflection yoke has only one pair of rings and they are where you position the raster. The magnet assembly below that is used for beam shaping and has multiple pairs of rings.
 

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Discussion Starter #7
That's what I needed to know.
So I'll set the position with the one nearest the screen and the focus with the lower one, the one nearest the crt plug/board assy.
Thanks very much.
 

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Focus is done mechanically with the lens, and electrostatically with the focus control on the block with the G2 and Focus controls. The magnets on the neck of the CRT affect the shape of the beam so that you get even response in the horizontal and vertical directions. When you display a dot, then adjust focus, it should open and close in a circular pattern and the center should not shift away from the middle.
 

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Discussion Starter #9
Since the green is electrically non-adjustable, I guess I should electrically center everything (there is an option in menus to reset to factory original settings), hook up my color dot generator, cover the red and blue lenses, and set green up first. Then do the rest. I think that the first magnet the beam encounters, the one nearest the yoke connector, would be the one for centering and the one nearest the crt screen would be for shaping it, right?
So I would first do a placement and then go to the other ring (there are two tabs right next to each other for each ring...maybe two magnet rings right next to one another???) and use it for shaping the dot? Then back to the placement ring and finish with the shaping ring?
Like I indicated, I've done a lot of regular single crt work but none but this set for projection models. Changing the coolant juice sure was fun...but I'm glad I got enough to do all three modules. By the way, for the Magnavox set in question, I used a little bit over 1 liter of coolant.
 

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The green is completely adjustable in the service level convergence, IIRC. I know it is on all of the Philips sets I can recall in this vintage. I suggest that you get the service literature for the set and review it. It will likely answer the questions that you have definitively, where I can only go from memory. I cannot research and step you through the process. This is far beyond the scope of the forum. If you need that level of consulting you will have to contact me directly.
 

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Discussion Starter #11
Thank you very much, I didn't mean to overstep my bounds. Just wanted some assurance is all.
It seems to me that I should do a static setup first then an electrical. I hope our dialog is helpful to others. The forum has been very instructional to me, thanks again!
 
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