The purity rings are adjusted along with yoke positioning. This has changed because either the crt has become magnetised (you should have a degauss coil before adjusting purity) or the yoke has moved (the rubber wedges compress over time altering the yoke positioning) setting these up you’d adjust the yoke position in conjunction with the purity rings. By tilting and wedging the yoke the geometry can be adjusted as well as through normal controls. Very few people know how to do this correctly
Great video and very interesting. I have Learned all about Purity and convergence adjustments via the rings and thank you for sharing the knowledge. The picture was very much improved and worth doing, You also have a great way of explaining things. You sound very much like my friend in Texas and when I first saw your videos I was sure it was him lol. Keep it up, I like this channel 👊
Thanks so much for this man. Finally someone just explained the rings and actually used them and described what each one does. Finally an upside to this this CRT popularity resurgence. People who know how they work begin to appear.
Wow thank you so much for this, a lot of the videos i was looking up weren't as descriptive as this one. I have a Sharp 27C530 and its a beautiful TV with component and S-Video but there was an awful red marking on the corner. I assumed it just needed a deguassing but even after using a wand along with power cycling, the mark persisted. I had opened it up recently to kinda have a look but it seemed overwhelming since i didnt even have a clue at what i was looking at but this video along with the service manual and some additional research has made me significantly more confident in what to look for when attempting my repair. you're probably already aware that theres a tool specifically for convergence adjustments but theyre a little expensive where as a jewelers loupe can a achieve a similar result to have a magnified look at the adjustment of the red blue and green colors. Thank you for this video and i hope om able to restore the purity of my CRT. 🤞
I just picked up this exact tv for free on marketplace with remote all in pretty much perfect condition. I will know were to go for advice now thanks for the video
Really appreciate you making this, I've got the original remote on the way right now and this is going to be a world of help opening it... this is a different beast that my 20" Sylvania. I'm assuming you had to mess with the yoke - did you have any issues with it not sitting flush against the tube? My Sylvania did that and I had to lay it face down and tighten it to fix it... I'm worried about handling this one due to the weight so if that happens again I'm screwed lol edit my yoke is BONDED so it's strip time
Thank you for this. I was able to get into my trinitron with this info and apply a lot of your settings. This DRASTICALLY improved the geometry. However, a day or two later the infamous bow came back. I'm thinking there's an issue with how I mounted the yoke and it may have slipped again. Probably need stronger adhesive on the wedges. Any tips on holding that thing in place when adjusting? The moment I come back around to the front to check changes (mirror doesn't let me look closer) the yoke is thrown off. I found that using the top wedge and leaning it in place helps, but not much. Any pro tips?
I usually just use whatever wedges I get and glue them to the back, then glue the yoke to it after tightening the screw down to hold it in place better
