Service manual

NOTE: The two processors in this book have different LED patterns. Refer
to Section 4.7 for interpreting <REFERENCE>(XRP) LEDs.
The large yellow LED at the bottom of the LED array is ON if self-test
passes and OFF if self-test fails. (Here self-test means both the on-board
power-up test and the extended CPU/memory test.)
On the boot processor module, the red LED next to the yellow is OFF.
This LED, which is controlled by the SSC chip, is ON on all the secondary
processors.
The six red LEDs on top are all OFF if self-test passes. If any of the LEDs
is ON, self-test failed and the LEDs contain a binary error code. The error
code corresponds to the number of the test that failed in hexadecimal. In
the six error LEDs, the most significant bit is at the top, but the lights have
a reverse interpretation — a bit is ONE if the light is OFF.
For example, assume a processor fails self-test (yellow LED is OFF), has a
minus sign (–) on its STF line, and shows the following pattern in its top
six LEDs:
TOP
(MSB) on 0
on 0 = 0
off 1
off 1 = E
off 1
on 0
BOTTOM
The failing test number decodes to 001110 (hex 0E, decimal 14). If you then
ran the ROM-based diagnostic 0 with TRACE ON, the last test number you
would see displayed is T0014.
When any of the six red error LEDs is lit, a failure has occurred during
testing. There are three sets of power-up self-test: KA62B power-up tests,
CPU/memory tests, and optionally the VAXBI adapter (DWMBB) tests.
Interpretation of the processor board error LEDs depends on which set
of tests was running at the time of failure. Table 3–2 decodes the LED
conditions.
3–20 VAX 6000 Models 300 and 400 Service Manual