After a number of years your wonderful big screen may not have the sharpness that it
once had. If this is your situation then read on. There are two types of focus needed
on conventional rear projection tv's. Optical and Electrical
First round up two wash rags or dish towels. Then remove the back from your set.
Locate the "Focus Block Assembly". Turn on the set and let it warm up for about
15 minutes. Feed a signal into the set, preferably something with stationary
graphics. Then determine which controls are for which colors. There are controls
for Focus and Screen. Do not adjust the Screen controls.
Choose the color you want to adjust first, the place rags over the other 2 colors
lenses. While watching the picture adjust the focus control back and forth until
you have the sharpest image. On some sets you may have to peer through the inside
of the set to see the image. Reposition the rags and repeat for the other two colors.
On to Optical focus!
This adjustment is almost always done from the back of the set. Locate the set
screws/wing nuts. As before place rags over two lenses. Unlock the wing nut and
slide the screw in its groove, until you have achieved the optimum focus for the
entire screen. You can never get perfect focus over the entire screen. You will have
to sacrifice one area in favor of another. Repeat for the other colors.
Reassemble the set and sit back and savor the money you saved on a service call.
