[comp.sys.apple2] Problem with Xebec 'Slider' disk drive

cgreen@s1001.essex.uk.ac (Chris Green ISBD) (12/24/90)

>>>apple2/general 76 cgreen(915)23dec90 18:21 
TITLE: Xebec 'Sider' disk drive problem
I have one of the above disk controllers and drives which started
developing an intermittent error a while ago.  The error now seems to 
have become permanent.  The symptom is that it will not boot (rather
a fundamental sort of symptom!), when the system is powered up you
are just dropped into the monitor.

Running the diagnostics produces the following:-
    TESTING ROM
    TESTING HOST ADAPTER
    TESTING CONTROLLER
    I/O ERROR:  SENSE BYTES NOT AVAILABLE
    
    I/O ERROR:  SENSE BYTES NOT AVAILABLE

    RAM TEST FAILED

Does anyone have any idea what this may mean?  I have tried all the
obvious things like reseating chips, checking plugs etc. but to no
avail.  Symptoms are identical in another Apple system so the problem 
just about has to be on the interface card or in the disk drive.

As a final resort who/what/where does Xebec support come from?

Chris