Technical information

2.1.2.3.5 Video Levels and Cutoff Voltages

Proceed as follows.

1. Select pattern C, the full screen raster and press the spacebar four

times for a black field:

a. Set RV600, RV631, RV651, and RV671 (cutoff potentiometers) fully

clockwise, as viewed from the video card shield.

b. Set RV632 and RV652 (gain potentiometers) fully clockwise, as

viewed from the top of the video card.

c. Set the Brightness control to center detent (midpoint), and the

Contrast control to midpoint.

d. Adjust G2 so that the screen is just not illuminated. Set the

Brightness control to maximum.

e. Adjust the cutoff potentiometers for a correct white color point.

f. Set the Brightness control to center detent (midpoint). If

necessary, adjust G2 to ensure that the screen is just not

illuminated.

2. Select Pattern B, 50 mm square box and press the spacebar three times

for a white box.

3. Ensure that the Contrast control is at midpoint.

4. Adjust RV652 (green) and RV632 (red) for correct white color points.

5. Set Contrast to maximum.

6. Set RV600 to midpoint.

7. Select pattern D, gray scale blocks.

8. Check, at maximum and minimum contrast, that the gradation of the

blocks is even from black through white with no color tinges.

9. Check that there is no color smearing.

If steps 8 and 9 are not satisfactory, repeat this complete procedure.

Note: The use of a color analyzer is recommended for steps 1e, 4, and 6.

PS/2 Displays Maintenance Manual

Video Levels and Cutoff Voltages

2.1.2.3.5 - 1