Service manual

Another drive problem with early machines concerned computers that reported 'Drive empty' when it was
occupied. This will occur if there is no power to the disc drive, so check that the power connector is not
loose, and if it is OK, check that 5v, 0v and 12v are all present on the drive crimp connector.
Test Equipment
Approved Service Centres with PET, PORT and FIT Test equipment often comment that although the
installed Filing System and Language ROMS function correctly within the BBC Unit under test, the Acorn
test equipment fails that area. This is due to the particular ROM/EPROM having the wrong CRC value
when that device is checked in accordance with the test firmware - this is particularly prominent since
Filing Systems and Languages are often updated. Latest versions of the test software are available from the
Spares department - but the problem might then show up as failing earlier machines!
This should not generally be seen as a failure in the machine.
The PET tester instructions commented on the availability of extensions to the PET tester that would test
the Disc and Econet upgrades - these were never produced, and are not available. The B+ test equipment
available is the PORT tester with further software.
Service Reports / Obtaining Spares
Attention should be drawn to the Terms and Conditions of receiving payment for work carried out under
warranty, and ordering of spares from the Spares dept. at Acorn.
A number of ASCs are submitting orders below the minimum £20 amount without prior arrangement with
Acorn and therefore resulting in frustration when the Order is returned to them. Orders must contain the
ACORN DESCRIPTION and PART NUMBER of the items required. If no part number is supplied, the
order may well be returned.
Service reports must enclose the parts which were replaced, otherwise no replacement parts will be issued.
It is imperative that service reports are returned swiftly after the repair. The service report should indicate c
learly the items removed, complete with the part number. The removed parts should be sent under the
same cover, securely packaged.
All Service Reports should be filled in as fully as possible with the serial number of the defective
equipment written in full. The new service report forms have a box marked for the serial number with a
square for each character in the serial number. Please ensure that all boxes are filled in.
If a particular Acorn spare part is required individually or in quantities costing less than the specified £20
then an alternative is to contact a mail order company that stock Acorn spare parts; they are:-
Doc. 999,0031 December 1987 -9- Acorn Engineering News