Agilent Technologies HP 8719D Service Manual page 278

Display Tests
These tests do not return a PASS/FAIL condition. All six amber front panel
exit the test. If any of the six LEDs remain on, the test has failed.
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the A19 GSP board. The CPU writes all zeros, all ones, and then a
the CPU repeats the walking 1 pattern until CPRESETI) is pressed.
DRAM cell.
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DRAM and then verifying that it can be read back.
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each bank and then writing all ones to one location in each bank.
F'inally a walking one pattern is written to one location in each bank.
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write and read shift register transfers. It also checks the video signals
LHSYNC, LVSYNC, and LDLANK to verify that they are active and
toggling.
60 outputs. Confirms that the analog video signals are correct and it
verifies their functionality.
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high.
Test patterns are used in the factory for adjustments, diagnostics, and
troubleshooting, but most are not used for field service. Test patterns
are ,executed by entering the test number (62 through 76), then pressing
labels blanked. To increment to the next pattern press softkey 1, to go back to a
previous pattern press softkey 2. To exit the test pattern and return the softkey
labels, press softkey 8 (bottom softkey). The following is a description of the
test patterns.
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of the A18 display and checks for color purity.
Checks to conllrm that the CPU can communicate with
Tests the DRAM on A19 by writing a test pattern to the
Tests the VRAM by writing all zeros to one location in
Verifies that the GSP is able to successfully perform both
Verifies that the intensity DAC can be set both low and
Displays an all white screen for verifying the light output
Service Key Menus and Error Messages
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