Service manual

Figure 1-3: Printer test
Disc interface test
The screen will clear and the following will be displayed:
FLOPPY DISC TEST VX.XX DEALER
Passed Write Protect Test.
Passed Verification Test.
Running Write Track Test 0, Drive 0
Remove the test disc from drive :0
Insert the BLANK DISC in drive :0
The BLANK DISC needs to be F Map
Insert the blank scratch disc, and the write track test
continues, displaying the following on the screen:
Working Track 76 Sector 04 Head 00
Disc Address used &000BF000
The read track and erase track tests are now complete.
When you are requested, put the test disc back in drive
:0. Press the space bar to continue.
If the write protect test fails it will corrupt the test disc.
You will then have to replace it with a new copy. A sign
of this corruption is that a file called ! DISC_FAIL will
appear on the disc, and the disc will not boot.
If errors occur during the read test, a maximum of 12
read errors may occur per sector before the next sector
is read. A total of 6 sectors are tested.
Note: During the soak tests only the write protect and
verification tests are executed (see the section entitled
Performing soak tests on page 1-17).
Action if floppy disc drive fails
If there is no desktop icon, check the CMOS RAM
configuration for "floppies 1" and reset if necessary.
Disassemble the machine (see Part 2 - Disassembly
and assembly) and check that both the 34 way data
cable and the 4 way power cable are securely
connected at the rear of the drive. Also check that the
data cable is connected to the main PCB at PL10.
Using a voltameter, check that OV and +5V are present
on the drive power cable and OV on pins 2 and 3, +5V
on pin 1 (conductor 1 is marked with white on the
cable). If there is no power, inspect the crimps inside
the connector shell and repair or replace if possible. If
the failure is with the PSU itself, return it to an Acorn
Authorised CSW for repair.
Check the data cable by substituting a known working
cable and retesting.
Check that IC38 is located securely in its socket.
As a final measure, try substituting a known working
floppy disc drive. Depending on the outcome of this
test, return either the main PCB or the floppy drive to
an Acorn Authorised CSW for repair.
IIf an icon is present but an error occurs during
access, disassemble the machine and check that the
34 way data cable is correctly connected both at the
rear of the drive and on the main PCB PL10.
Check the data cable by substituting a known working
cable.
Part 1- Fault diagnosis and repair Issue 1, November 1991 1-11