[mickeymoose2000]

I have a Sony 1252q with a very noticeable burn across the entire lower third of the blue tube. There is no burn any where on the upper two thirds and there is no 4:3 burn. I have acquired a used replacement tube in excellent shape ( no burn ). It is my intention to make the change myself.


(Without getting to technical, I'm looking for general feedback.)


1. what would cause a burn in this configuration?


2. what setup changes / precautions should be made to avoid this

happening to the new tube?


thanks.. mike

 

[MYoung]

The burn is caused by the picture (usw. burn => tube driven too hard or just old and/or heavily used). What you describe seems to be was a result of displaying widescreen movies. Is the burn on the blue tube? If you watch widescreen movies you are going to get widescreen wear (or burn if you overdrive the tubes or watch movies 24/7 for a while). If you are getting a decent replacement tube and your other tubes are near mint or better then I'd recommend centering the raster, increasing phosphor area (within reason - don't make it as big as you can, just a bit smaller than max. to prevent catastrophic tube failure I guess). With a larger phosphor area used you will get more light output and thus you won't have to drive a smaller portion of the tubes harder. CRTs wear and burn are aggrigate so the little things can make a difference. A bigger factor is contrast level. Enjoy you machine but don't overtax it if you plan on making it last a long time. Hope this helps a bit. Good luck!

 

[wireburn]

I would be willing to bet that burn pattern was caused by displaying a static outdoor image with a nice, blue sky.


See if you can push the widescreen image up the face enough to get away from the burned area. If your space allows for higher/lower than normal screen positioning, this may work in your room.


-Mike

 

[mickeymoose2000]

mike (myoung) I appreciate your input and will keep your feedback in mind as I set up the new tube. What I was really trying to figure out was.. not why a tube burns ... but why only on the bottom. If the problem was a widescreen burn I would have expected the burn at both the top and bottom or actually vica versa....anyway I think mike (wireburn) may be onto something.

when I bought this unit the burn on the bottom was only slight but your comment reminds me that I was told that at one time this unit had been used in a golf pro shop hooked to a simulator.


can I assume that damage started at that time ( a static image containing ground and sky ) would continue to burn faster in a certain area of the tube face even after being remove from that environment due to excessive load in the tubes early life?


mike