Originally Posted by Mr Bob
Mit does not use goo for immobilizing the focus. It uses black felt duvetyne tape on most HDreadys, and wingnuts on some of the 73" models.
Well I took the handfulls of what looked like solidified glue or sealant (Greyish in color, like hardened merangue) to the trash when handed to me by the ISF tech working on the set. I assumed they locked the focus rings, but it must have been what you were referring to below, some other aspect of the guns.
If you are playing with anything that involves dried goo, you must be in the set underneath, at the CRT necks under the panel at the speaker grill. In which case you are playing either with centering magnet rings or astigmatism correction magnet rings.
Ok, that makes sense since there was was much adjustment going on at the time on the guns themselves.
The focusing seldom changes. Overscan reduction is a great enhancement to your pix, but causes copious errors that need to be corrected, in the geometry and convergence. Not the focus, which stays the same.
Then I likely do not need to touch the focus if it doesn't change that much, but I would like to know how to change it...you know, just to see if I can improve it just a wee bit. But yes, I did have to do much work in the geometry (adjusting fine green so the other guns followed suit). Its not perfect, but its close enough for my tastes. The only problem now is that I can't get convergence spot on in the corners, but I live with that.
Unless you are using the shimming of the CRT array technique rather than totally the sm registers technique. If you do it by shimming the CRT array forward/upward towards the mirror, then of course the focusing needs to be redone. If the regular sm registers only method, not.
Ok I know thats english because I can read the words, but I can't comprehend it
Anyhow I'm not messing with anything at this point in time.
Yes, but to do it right, you gotta de-stick the duvetyne tape, do the focusing, and put that tape back against the plastic surfaces of what moves and what doesn't move. I use a long, thin screwdriver shank to gently de-roll the tape off, so I can re-use it again after refocusing.
Ok, now this tape (assuming its still in there) is this on the plastic rings at the top of the gun closest to the mirror? Is that the part I'd turn? I see other levers on the stem of the gun that I know not to mess with....
I hope you are doing it in sm. I know there is a way to do it in user, but have no experience on that from which to answer your question.
Right, in SM there was a way on those models to do a fine convergence..then save it as the default factory reset.
Too bad you're not using it for HD. Fully cleaned and dialed in, it would still kick ass over anything that is 720p out there, and lots of the 1080p stuff.
Its nice, but its small
I grew too accustomed to DLP front Projection.
Since it's been a few years since you had the optics cleaned, they are definitely dirty again, and in need of professional grade cleaning. Esp. if you are using it for 8 hours a day.
I imagine.....Sears wanted to send guys out to clean the set and I always refused, figuring some dude would come out and monkey around with the set doing god knows what. Are there guides for CRT cleaning out there?
Or is this something that needs to be done by ISF tech and calibrators.
If your calibrator was just a typical ISF calibrator with little or no experience in CRT tech, your optics have prolly never been cleaned at all. If not, then the before and after difference you'd see re. optics cleaning would be staggering, esp. at its present age and daily usage.
Chuck..someone, a regular over at HomeTheatreSpot back in the day, he was a very nice guy, spent many hours at the house, significant improvement in picture when he was done, using test generators, reprogrammed out the red push in the color decoder, etc. not sure if he did or did not clean the optics.
I should say he did alot of adjusting...and then I went back months later and tweaked the geometry (had a few speed bumps I worked out) and overscan and so forth. With videogames at 1080i I had to adjust the overscan a little more extreme, and had to re-do geometry and convergence again, but its been awhile since I've messed around in the service menus...but I was always careful when I was in there.