Adjustment Procedures
TDS 684A, TDS 744A, & TDS 784A Service Manual 5–21
Display Assembly Adjustment
STOP. It is not necessary to do this procedure to perform a complete adjustment.
Only use this procedure to adjust the display assembly if it has been repaired or
if brightness and contrast have become unsatisfactory.
Equipment
Required One 6X magnifier(Item 15)
One J16 Photometer with a J6503 Luminance Probe (Item 16)
1. Access the inside of the oscilloscope: See Removal and Installation
Procedures in Section 6 to remove the cabinet.
2. Adjust the display rotation:
a. Display the Composite test pattern:
HLeave the oscilloscope powered off.
HSet the DIP switch, located near the front of the A11 DRAM
Processor/Display, as follows:
Switch No. 1 2 3 4 5 6 7 8
Open X X X
Closed X X X X X
HPower on the oscilloscope.
HPress SHIFT; then press UTILITY.
HRepeatedly press the main-menu button System until Diag/Err is
highlighted in the pop-up menu.
HRepeatedly press the main-menu button Area until Display is
highlighted in the pop-up menu.
HRepeatedly press the side-menu button –more– until Composite
appears in the side menu. Push Composite.
HPress the main-menu button EXECUTE; then press the side-
menu button Ok Confirm Run Test.
b. Adjust R401 (TRACE ROTATION) to minimize the display’s tilt. Use
the frame around the display as a reference. R401 is the second
adjustment from the fan.

Rotation, Brightness, and

Contrast Adjustment