Texas Instruments 990 Installation And Operation Manual page 31

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6. Examine the remaining indicators (KYBD DATA) on the back of the display unit. The
indicators should be lighted in the following pattern:
Pattern: Off On Off Off
Indicator:
7
6 5 4
If this pattern is displayed, skip to step 8.
Off
3
Off
2
Off On
o
On
On
p
s
7. Ensure that the keyboard cable is properly connected to the display unit and repeat
steps 5 and 6. If the pattern still is not displayed correctly, call service personnel.
8. The Parity indicator (P) should be lighted. If this condition is not met, caB service
personnel; otherwise, continue with this procedure.
9. Adjust display to provide the best possible image by using the following controls:
• Adjust the audio alarm volume control on the unit's right side to the midpoint of
its range. This knob controls the volume of the "beep" tone and may be adjusted
during operation to provide a louder or softer tone to suit the environment.
• Adjust the front knob on right side of unit to control the brightness of display.
If unable to obtain a satisfactory image, call service personnel; otherwise, continue with this
procedure.
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Digital Systems Division