Agilent Technologies 8719ET Service Manual page 268

Service Key Menus and Error Messages
Service Menus - Internal Diagnostics
Test Pat 6 − Displays a 16-step gray scale for verifying that the A19 GSP
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board can produce 16 different amplitudes of color (in this case, white).
The output comes from the RAM on the GSP board; it is then split. The
signal goes through a video DAC and then to an external monitor or
through some buffer amplifiers and then to the internal LCD display. If the
external display looks good but the internal display is bad, then the
problem may be with the display or the cable connecting it to the GSP
board. This pattern is also very useful when using an oscilloscope for
troubleshooting. The staircase pattern it produces will quickly show
missing or stuck data bits.
Test Pat 7 − Displays the following seven colors: Red, Yellow, Green, Cyan,
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Blue, Magenta and White.
Test Pat 8 − This pattern is intended for use with an external display. The
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pattern displays a color rainbow pattern for showing the ability of the A19
GSP board to display 15 colors plus white. The numbers written below
each bar indicate the tint number used to produce that bar (0 &100=pure
red, 33=pure green, 67=pure blue).
Test Pat 9 − Displays colors Red, Green, and Blue at four different
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intensity levels. You should see 16 color bands across the screen. Starting
at the left side of the display the pattern is: Black four bands of Red (each
band increasing in intensity) Black four bands of Green (each band
increasing in intensity) Black four bands of Blue (each band increasing in
intensity) and Black. If any one of the four bits for each color is missing the
display will not look as described.
Test Pat 10 − Displays a character set for showing all the different types
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and sizes of characters available. Three sets of characters are drawn in
each of the three character sizes. 125 characters of each size are displayed.
Test Pat 11 − Displays a bandwidth pattern for verifying the bandwidth of
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the EXTERNAL display. It consists of multiple alternating white and
black vertical stripes. Each stripe should be clearly visible. A limited
bandwidth would smear these lines together. This is used to test the
quality of the external monitor.
Test Pat 12 − Displays a repeating gray scale for troubleshooting, using an
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oscilloscope. It is similar to the 16 step gray-scale but is repeated 32 times
across the screen. Each of the 3 outputs of the video palette will then show
32 ramps (instead of one staircase) between each horizontal sync pulse.
This pattern is used to troubleshoot the pixel processing circuit of the A19
GSP board.
Test Pat 13 − Displays a convergence pattern for measuring the accuracy
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of the color convergence of the external monitor.
Test Pat 14-15 − Displays crosshatch and inverse crosshatch patterns for
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testing color convergence, linearization alignment. This is useful when
aligning the LCD display in the bezel.
10-14
8719ET/20ET/22ET
8719ES/20ES/22ES
RF Network Analyzers
Service Guide