Service manual

Memory test
The screen will clear and the following menu is displayed:
MEMORY TEST VX.XX DEALER
Amount of Memory 2 Mbytes
Running four phase memory test.
Lower memory limit &000088BC
Upper memory limit &00141EA0
Phase one : incrementing pattern....
Phase two : Cycling bits ..............
Phase three : TRUE Hierarchy ..........
Phase four : FALSE Hierarchy ..........
PASSED.....
PRESS <SPACE BAR> to continue
You should check that the amount of memory displayed
is the same as that you made a note of at the end of the
section entitled Checking the memory size on page 1-7.
Note: The upper and lower memory limit can vary
slightly between releases of the test software, hence
approximate values are given.
Action if the memory test fails
If the test fails, refer to the sections entitled Action if
main PCB fails and Action if upgrades fail on page 1-3.
Battery backed RAM test
The test continues by testing the battery backed RAM.
The following is displayed on the screen:
CMOS TEST VX.XX DEALER
Copied CMOS RAM into main memory.
Passed CMOS RAM Configuration.
Passed Read - Write function.
Copied CMOS RAM from main memory.
Passed CMOS RAM Verification Test
THIS SUB TEST HAS PASSED
PRESS <SPACE BAR> TO CONTINUE
During the Read - Write function test of the CMOS RAM
you will be requested to enter the file name for the
CMOS data file that should be used for this test. This file
contains some of the CMOS data, and will change with
different configurations of unit (i.e. IDE fitted etc). You
should press Return to use the default data file. If you
need to use a specific file, not the default, then enter the
path and filename of the data file to be used (this is the
one you created in the section entitled Creating a CMOS
test data file on page 1-7).
Action if the battery backed RAM test fails
Check that the CMOS test data file is correct (see the
section entitled Creating a CMOS test data file on page
1-7). if the test still fails, then refer to the section entitled
Action if main PCB fails on page 1-3.
Note: if this test fails you cannot rely on the results of
the remaining tests. This is because the CMOS RAM is
used to control the test sequence and store the results.
IDE hard disc drive interface test
The screen will clear and the following will be displayed:
IDE INTERFACE TEST VX.XX DEALER
Drive 4 is IDE
ADFS::4 is IDE drive 0
IDE drive : 0
Description : <aaaaa> <bbbbb>
Firmware version : <cccc>
PASSED byte check
THIS SUB-TEST HAS PASSED
PRESS <SPACE BAR> to continue.
Note:
<aaaaa> Drive manufactures name (e.g.
Conner Peripherals)
<bbbbb> Drive model number (e.g. CP3044)
<ccccc> Firmware version number (e.g. 2SA4.53)
Note that during the soak test the IDE drive interface
test is not executed (see the section entitled Performing
soak tests on page 1-17).
Action if the IDE hard disc drive fails
Check that the machine configuration is set for "
IDEdiscs 1" and reset if necessary. Disassemble the
computer using the procedure given in Part 2 -
Disassembly and assembly and check the following:
• the 40 way data cable is securely connected to the
drive and to PL9 on the main PCB.
• the 4 way power connector is correctly attached.
Try substituting a known working data cable for the
existing cable and retest.
Using a voltmeter confirm that the following voltages
appear on the 4 way power connector:
• OV on pins 2 and 3 (black cable)
• 5V on pin 4 (red cable)
• +12V on pin 1 (yellow cable)
If a voltage is missing, check the crimps within the,
connector shell and repair if possible. If the problem is
within the PSU then you must return this to an Acorn
Authorised CSW.
Part 1- Fault diagnosis and repair Issue 1, November 1991 1-9