Specifications

SQ: 1-12
RS3: Service Quick Reference Guide
Troubleshooting
Console Power-Up Tests (continued)
Item DefinitionTest
Console
(cont.)
EDAC Test This is a test of the Error Detection and
Correction circuitry. An error is purposely
written into a number of RAM addresses to
verify that the EDAC will correct it. If the card
has failed the EDAC test and passed the RAM
test there should be no fault that would corrupt
data. The card should operate for a period of
time but could reset the console frequently.
The processor card s hould be replaced as
soon as possible.
Four Meg RAM Test An address and data test is run on all of the
RAM on the processor card. If a failure is
indicated here the console will probably not run
reliably.
NOTE: If a single bit error is detected during
the RAM test, the Error Detection and
Correction (EDAC) circuit will correct for a
single RAM chip failure. The EDAC test on the
processor card will be bypassed (indicated by
the E DAC test also being backlit) and the
console will not halt on this screen but will start
up from disk in the normal way. A “Console
Weak RAM Chip,bit XX” alarm will be
generated and placed on the Active Alarm List.
Instruction Set Test This is a test of the microprocessor itself. An
elaborate algorithm is run using many of the
varied instructions to verify the i ntegrity of the
microprocessor. If a failure is indicated here,
the processor may be bad and the card should
be replaced. Power regulator voltage should
also be checked.
Processor Boot
Version
This number indicates the software revision
number of the ROM memory parts of the
processor c ard. The ROM contains the
information that the processor needs to run the
power-up diagnostics and the routine needed
to load the Boot Disk into the console in order
to begin operating.
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