Service manual

10 Troubleshooting
Self-Test Results
A code of 00XX.0001 next to the MEM mnemonic indicates no errors
(the XX is the total amount of memory installed in the system [in
hexadecimal]). Verify that the mnemonic matches the amount of memory
in the system.
If an error is detected, refer to Section 2.2.1 to determine which module
needs to be replaced. There is no further memory test in the system
exerciser. The self-test will run complete memory tests if you:
1. Install a loopback on the communication port.
2. Enter TEST B.
3. Read the results on the screen during the test.
A code of 0XXX.0001 next to the MEM mnemonic indicates no errors (the
XXX is the number of pages of memory tested during the last pass of the
exerciser [1 page = 512 bytes]).
The following test will not work on this system:
>>> t 80000106
?>>> B
If this test is invoked, the system will have to be halted in order to get
control in console mode again. If the DZ drivers were also invoked,
CTRL C
does not get you back to the console mode.
2.2.1 Additional MEM Information
The code for MEM in the configuration table indicates the amount of
memory available if no errors are detected. For example, 0010.0001
indicates that 16 Mbytes of memory are available (10 in hexadecimal =
16). The second MEM line in the configuration table contains two 8-digit
codes, one of which is displayed when errors are detected. The first
code repeats the amount of memory in the system, and the second code
(displayed only if an error is detected) contains the location of the failed
memory.
There may be up to six more 8-digit codes listed in the configuration
table. These codes represent the cache memory located on the system
module. If this is seen, run the memory test again to see if the results
are duplicated. If so, the cache is bad and the system module has to be
replaced.