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TROUBLESHOOTING AND DIAGNOSTICS
[4] SELFTESTS (up 9153/54A S/N Prefix 2515A and Below)
Refer to Figure 8-2 for location of LEDs metioned in the following text.
Selftest routines can be initiated in 3 different ways:
1. At power-on, a selftest of the PROCESSOR, ROM, HP-IB chip, RAM, BUFFER RAM and both drives are
performed.
The Winchester
disc drive test includes reading and writing sectors, checking the spindle
speed, and checking that the error correction circuitry functions correctly by introducing errors and cor-
recting them.
The yellow fault LED stays on if the power on selftest fails.
2. An "Initiate Diagnostic" may be given from the host computer.
Tests normally
run at power-on
are
done.
3. If no host computer is available, a service test point can be grounded causing the 9153A/54A to go into
the diagnostic test mode.
It reads the HP-IB switch to determine which test should be performed.
The
yellow (fault) selftest LED first blinks (to show that the LED
works) and then the test selected by the
switch settings is performed.
A successful test is indicated by the LED blinking 5 times.
A failure causes
the LED
to stay on for S seconds.
If the test point remains grounded the test is repeated.
When
the
ground is removed
from the service test point, the 9153A or 9154A will go through the power-up se-
quence and will again be in the peripheral mode of operation, waiting for commands over the HP-IB.
The results of a successful test are displayed by the yellow fault LED blinking five times (once per second)
followed by a complete power-up sequence.
A failure causes the yellow fault LED to stay on.
The following discussion will cover items 1 and 3 above.
TEST PERFORMED
DURING
POWER-ON
At power-on, a sequence of tests checks the PROCESSOR, ROM, HP-IB chip, PROCESSOR
RAM, BUFFER
RAM, and the drive(s). The Winchester disc drive test reads and writes sectors,checks the spindle speed, and
checks that the error correction circuitry is functioning.
When the 9153A or 9154A is first powered on, the red Winchester disc drive on-line LED and the yellow
fault LED come on. The yellow fault LED will come on as each of the tests in the power-on sequence is ex-
ecuted and remain on until each test is finished.
In the case of a 9153A, the red Winchester disc drive on-
line LED goes off and the red flexible disc drive LED comes on when the flexible disc part of the testing
begins.
i
A failure of a test in the power-on sequence is signalled by the yellow fault LED blinking with specific pat-
terns as explained below.
If the yellow fault LED remains on continuously after the red Winchester disc drive on-line LED and the
flexible disc drive access LED have gone off, something has failed that prevents the yellow fault LED from
communicating the failure through its flashing codes (for example, processor or RAM
failure).
Individual
tests should then be run to attempt to isolate the problem.
Refer to the next subsection MANUAL
EX-
ECUTION OF SELECTABLE SELFTESTS.
If the disc drive powers up and shows a flashing fault LED failure indication, this indication will remain on
until you successfully do an Initiate Diagnostic command, an Initialize media command, or again power up
8-2
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