HP 16500A, Service Manual, Page: 87 / 144

Disk Test
This test checks both disk drives for the correct disk format and checks the ability of the system to read
from and write to a test track on both disks. If the disk cannot be identified, the test is considered to have
failed for that disk drive. If a disk cannot be detected, the message "no disk" is displayed instead of the
pass or fail message.
Possible problems causing a failed message include the following:
A damaged or disconnected disk drive cable.
Wrong disk formatting or no disk formatting.
The disk write-protect tab set to the write-protect position.
Incorrect position of the address switch on the disk drive.
A faulty disk drive.
Faulty microprocessor board interface circuitry to the disk drive.
For Disk Test failures, verify the continuity and connection of the disk drive cables, use formatted disks,
and set the write protect tab on the disks to the unprotected position. The address switch on each disk
drive is set to the correct position when the disk drive is installed at Hewlett-Packard. A failure will occur
if the switch on a replacement disk drive assembly is set to the incorrect position. For the correct switch
position, refer to section 6-16, "Front Disk Drive Replacement," or to section 6-15, "Rear Disk Drive
Replacement." If the disk test still fails after verifying that the previous items are not causing failures,
refer to section 6-7, "Troubleshooting."
Intermodule Test
The Intermodule Test checks the functions of the intermodule timing correlation. This test fails if there are
any connections on the input BNC. For Intermodule Test failures in a mainframe, suspect a faulty
microprocessor board. For Intermodule Test failures in a mainframe connected to an expansion frame,
suspect a faulty mainframe interface board.
Note
The Intermodule Test screen shows the mainframe and expansion frame card
slots and the card identification code of the module located in each slot.
Color Display Test
The Color Display Test puts screen patterns and color screens on the monitor. This test is mainly used to
check for color purity. Usually, the purity problem can be solved using a degaussing coil. If some pixels
are not colored, then there is probably a problem with the Display RAM on the microprocessor board. For
Color Display Test failures, degauss the display. Refer to section 2-14, "Degaussing the Display." If the
Color Display Test still fails, suspect a faulty microprocessor board or a faulty color display monitor.
All System Tests
The All System Test will perform all the tests listed on the screen on the Mainframe Test menu, except for
the Color Display Test and the Expander Test. When the tests are complete, the status advisory for each
test changes from UNTESTED to PASSED or FAILED. The status advisory for the Color Display Test
and for the Expander Test remains UNTESTED and the status advisory for the All System Tests changes
from UNTESTED to TESTED.
Expander Test
The Expander Test is used during troubleshooting to check the data and control signals through the
HP 16501A expansion frame components.
HP 16500A/16501A - Service
6-18