i've got a pioneer elite pro96 RPTV. should any kind of periodic maintenance or service be done by a repair tech? i'm able to check and set the convergence myself.
About twice a year, you should clean the lenses, the back side of the screen, and the mirror with a damp soft cloth. (cotton or flannel) and dry with the same type of cloth. You can do this yourself, and unless you're having any other problems, you don't need a service tech. Vb
If you can reach the mechanical focus control without touching high voltage areas inside the TV, you can adjust that, too, yourself. But be sure you have a good test pattern with tiny dots near the screen borders as well as in the center. Also be aware that, if the focus control is truly mechanical such as a ring around the picture tube neck, once you move it you might find it difficult to put it back the way it was if you made things worse.
Playing the 200 TVL test pattern in AVIA, if you get the full horizontal resolution of 540 lines (per distance equal to the picture height @ 4:3) you shouldn't need to adjust the focus control.
what you are describing is not mechanical focus, it is beam focus. "mechanical focus" is confusing, but mechanical setup/focus almost always is used to refer to physical aim of the guns and optical focus. Beam focus/astig is done with astig magnets, electronic focus adjustments and zone astig, depending on which are available on the set. IMO it is clearer to use the terms optical focus/mechanical setup versus beam focus/beam setup.