Cutoff - DEC VAXmate Service Manual

IIIII
Monitor Adjustments
4.3.2
Cutoff
The cutoff control sets the threshold of the accelerator grid (G2) of the CRT.
If set too high, retrace lines are displayed on the screen. Display pattern 6
(the 400 line mode screen of E's) and follow these next steps to adjust cutoff
control.
1. Set the brightness control to maximum and contrast control to minimum.
See Figure 4-1.
2. Adjust the cutoff control (G2) (see Figure 4-2) so the raster is just barely
visible (almost at extinction).
3. Turn G2 clockwise about 30 to 45 degrees (Figure 4-4). The display
brightens. There should be no retrace lines visible. If you still see the
retrace lines, replace the monitor board.
4. Return the brightness and contrast controls to normal settings.
K' G R"S
I /
I /
I /
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o
G2 CONTROL ON MONITOR BOARD
LJ-0911
Figure 4-4 Cutoff Adjustment
4-6