Figure 31 The CONT., HOR. PHASE,
HEIGHT, V. HOLD, WIDTH, and V. LIN adjustments are at the top of the video
board.
18. Adjust an accurate VOM meter to the lowest DC volt scale capable of
measuring 5.0 V DC. Attach the black probe to the Lisa chassis. Locate the
HOR. PHASE potentiometer, labeled R34, which is second from the left as
you face the front of the video board. Turn around and face the rear of
the video board. Find the point where R34 is soldered to the printed circuit.
Insulate the red VOM probe with a piece of shrink tubing. Carefully touch
the tip of the insulated, red probe to the rightmost of the potentiometer's
three solder joints. (Note: if you do this while leaning over the front
of the computer, the 5.0-V joint will be on your left.) Be careful not to
short uninsulated probe tips to the steel card reading is out of range,
go on to step 19. If it's in range, skip to step 21.
19. Refer to Figure 5. Turn off the Lisa/XL. Face the rear of the computer
and unplug the power cord from the power supply. Unscrew the knurled knob
and remove the supply by pulling straight back. New units may offer some
resistance. Pull straight back.
20. As shown in Figure 32, find the access hole on the left side of the
power supply. With a long-handled 1/8-inch slotted screwdriver, tweak the
+5.00-V adjustment pot (RII) clockwise 1/16 of a turn. Reinsert the supply
and measure again (repeating step 18). If the meter still doesn't read +5.00
volts, repeat steps 18 through 20 until it does.
21. The Macintosh XL Screen Kit generally causes horizontal foldover which
manifests itself as an annoying 1/8-inch to 1/4inch white bar at the left
edge of the screen. Turn the horizontal phasing control (at the top of the
video board) counterclockwise until it's gone. Properly adjusted, the pointer
on the HOR. PHASE pot will typically indicate eleven o'clock. If you can't
adjust
Figure 32 The +5.00-V adjustment
can be reached through this access hole on the left side of the power supply.
the HOR. PHASE pointer past twelve o'clock, check for excess sealant and
remove it as noted in step 16. If the pointer turns fully counterclockwise
and you still have a foldover problem, check the +5.00 voltage adjustment
as noted in steps 18-20.
The next step requires accuracy and involves the use of a soft cloth
ruler (also known as a dressmaker's ruler). Use a good one. Because the
edge protectors on cheap rulers are only haphazardly cemented to the tape,
the first and last inches could be off by as much as 118 inch! Attempting
the final alignment procedure with an inaccurate ruler will prove futile.
Choose a