Maintenance Philosophy - IBM 5280 Maintenance Information Manual

The diskette drives need no scheduled maintenance. The
MAPs guide you in diagnosing diskette drive failures. The
MAPs refer to maintenance procedures in this manual when
an adjustment, service check, or F R U replacement is
needed.
All maintenance procedures are written with the
assumption that the drive assembly has been removed
from the enclosure and is fully accessible on a work surface.
It might be practical in some instances, to perform specific
procedures without removing the drive assembly. These
instances can best be determined by the individual
circumstances.
The head/carriage assembly and the drive hub and spindle
pulley assembly are adjusted and tested at the factory. The
drive hub and spindle pulley assembly are not field-replace-
able units. If the track 40 adjustment surface or the drive
hub and spindle pulley assembly are damaged, you should
replace the entire diskette drive assembly. The head/
carriage assembly is a field-replaceable unit.
Maintenance Ph ilosophy
The main differences between the 31SD diskette drive (for
the diskette 1) and the 51 TD diskette drive (for the diskette
1, 2, and 2D) are in the head/carriage assembly and the layout
of the diskette drive control card. Maintenance procedures
that are affected by such differences will provide two distinct
sets of instructions within the affected step. These distinct
differences will be labeled (31SD) and (51TD) as in the
following example:
1.
2.
3.
4.
Remove the cover.
Disconnect the cables.
(31 SD) Remove the head/carriage assembly.
(51 TD) Insert a clean piece of paper between the
read/write heads and remove the head/carriage
assembly.
Invert the assembly.
When the callout of a figure is not affected by the
difference between the drives, the 31 SD drive figure will be
used. In those instances where the callout is affected by
the difference, the 51 TD drive figure will also be used.
Maintenance Philosophy ix