Tip fro Rick Gladys: The procedure for
getting into the service menus of Zenith 851 and Runco Cinema Pro 750 projectors is:
Hold the "menu" button down until the Demonstration screen shows up,
Then on the remote, type: 9 8 7 6
This gets you into the Service menu of the projector.
As far as doing sizing and convergence on these older projectors
(and there are a lot of them out there), the best site I've found is cinemasource.com.
They've got a downloadable guide on how to adjust the 46 pots on these projectors, step by
step. Instead of guessing, you get PERFECT convergence everytime! I mean everytime! Razor
sharp picture on my 100 inch screen. I printed the whole thing out and keep it in a
binder. An invaluable resource for older projector owners who don't have all the new
computerized convergence gadgets on their projectors.
Brightness on these projectors can be improved too. Kroll has a modified prom chip for
these projectors that dithers the scan lines to fill in the black lines between the scan
lines (it lengthens the pixels that make up each scan line, filling in the black between
the scan lines), resulting in a smoother and brighter picture. They sell it for $99 and
from what I've seen from a friend, it's well worth it (mine is enroute from them). Beats
paying tons for a line doubler, especially since these units can't support them.