User guide

7
2-46 De-solder and discard the eight L-shaped pins that the CRT plugged into (figure
4) on the motherboard. NOTE: This step is required because the pins no longer
have a mating CRT connector that is insulated and so they would be a potential
shorting hazard to the instrument cover.
2-47 Solder the yellow wire on the 23V power cable (W3 included in kit) to connector
A1XA6 pin-7 on the bottom of the A1 motherboard (figure 4).
2-48 Tie strap the yellow wire on cable W3 to the existing motherboard wiring harness
(figure 4).
2-49 On the side of the A1A3 sheet metal shielding cage that faced where the CRT
used to be, there will either be a hole in the middle of the side or a notch where
the cage meets the motherboard.
Figure 4: A1 Modifications
2-50 If there is a hole in the middle of the side, then feed the 23V power cable edge
connector PCB, on cable assembly W3, through the hole and plug it into the
empty A1A3 card slot.
2-51 If there is a notch in the side of the A1A3 cage, then guide the W3 PCB connector
through that notch.
2-52 Reinstall the A1A3 high voltage power supply shielding cage. Ensure the W2
cable passes in front of the A1A3 cage so it will reach the display when installed.
2-53 Reinstall the A1C3 and A1A6/A7/A8 covers that were removed in step 2-27 and
engage cards A1A7 and A1A8 into their guide slots.
2-54 Reconnect all cable clamps that were disconnected from the A1A3 and
A1A6/A7/A8 assemblies.
2-55 On the old front panel assembly, remove the “Level” and “Intensity” knobs and
the retaining nuts underneath them.
2-56 Lift off the front panel keyboard overlay and set it aside.
2-57 Remove the eight 4-40 flat-head screws on the front of the keyboard assembly.