Yesterday I spent the better part of eight hours or so poking through hidden service menus, tweaking and re-converging my rear-projection television. As you may already know, projection TVs use three separate CRTs (one red, one green, and one blue) to project an image onto the screen. Over time, especially if the TV is moved, these CRTs can get out of alignment, resulting in ugly color bleeding and, if it gets bad enough, a warped picture.
My TV has been moved six times since I bought it, and I had never taken the time to do a full convergence. Now I wish I had. Over the past few weeks, the image has been especially bad, and I’ve converged the thing several times using the customer accessible multipoint convergence feature, but somehow it never seemed to stick. The colors would start to drift again pretty much instantly. Faced with the option of calling an ISF certified technician and paying several hundred bucks for a professional re-calibration or trying to do the job myself with no service manual and no training, possibly frying my expensive TV, I decided, of course, to do it myself.
A few Google searches turned up some useful information, most notably the 090/how2adj.html”>How to Calibrate a Television FAQ and this page/mitsu/others.html”>list of Mitsubishi service menu codes (the top three codes worked on my TV, a 2000-era WS46809).
For the most part, the TV’s service menus consist of virtually undecipherable abbreviations for hundreds of different settings. After haphazardly tinkering with a bunch of them to see what they did, I gradually started to feel more comfortable. “This isn’t too hard,” I thought to myself. “I wonder what this does?”
I had somehow managed to completely—and I mean completely—reset the orientation of the CRTs so that each was pointing in its own direction. Red was coming from somewhere off to the right, blue from the left, and green from the middle, which resulted in one hell of a nasty picture. Whereas before the convergence had been off by, at the most, a few centimeters in various places, it was now off by several inches almost all over the screen. Ack.
Resolving to stop playing around and get down to business, I brought up the convergence service menu, which is much nicer (and allows for much finer adjustment) than the customer-accessible menu.
To cut a long story short, after spending eight hours staring intently at a 12×13 grid aligning each point for each of the three CRTs God knows how many times, I finally managed to get the image looking just about right. Blue is still very slightly problematic in places, but I think I’m just going to have to live with that.
End result: It took a lot of hard work, a lot of scary messing around with cryptic service menus, and a great deal of squinting and head-tilting, but I now have a picture that, if I do say so myself, looks even better than it did the day I brought it home. I even managed to fix an annoying issue with the screen geometry being slightly warped on the left side, which I had thought I was just going to have to live with since it was like that when I bought it.
Hopefully I won’t have to do this again for a good long time.