HP 8753E Service Manual

Display Tests
These tests return a PASS/FAIL condition. All six amber front panel LEDs will
turn off if the test passes. Press m to exit the test. If any of the six LEDs
remain on, the test has failed.
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Dispkpu corn. Checks to con&n that the CPU can communicate with
the A19 GSP board. The CPU writes all zeros, all ones, and then a
walking one pattern to the GSP and reads them back. If the test fails,
the CPU repeats the walking 1 pattern until I&%?) is pressed.
DRAM cell. Tests the DRAM on A19 by writing a test pattern to the
DRAM and then verifying that it can be read back.
Main VRAM. Tests the VRAM by writing all zeros to one location in
each bank and then writii all ones to one location in each bank.
Finally a walking one pattern is written to one location in each bank.
VRAM bank. Tests all the cells in each of the 4 VRAM banks
VRAMhideo. Verifies that the GSP is able to successfully perform both
write and read shift register transfers. It also checks the video signals
LHSYNC, LVSYNC, and LBLANK to verify that they are active and
toggling.
RGB outputs. Confirms that the analog video signals are correct and it
verifies their functionality.
Inten DAC. Verifies that the intensity DAC can be set both low and
high.
Service Key Menus and Error Messages 1 O-1 5

HP 8753E Specifications

General

Brand	HP
Model	8753E
Category	Measuring Instruments
Language	English