Line Printers - Radio Shack TRS-80 Service Manual

SECTION
1
INTRODUCTION
This
Service
Manual
describes
two
Line Printers (Catalog
Numbers
26-1150 and
26-1152)
that
are
manufactured
for
Radio
Shack. The manual
provides
a
general description of the
units,
followed by
a
more
detailed theory
of operation
and
spare
parts information enabling
field engineering personnel to
service these
printers.
The
manual
is
aimed
at
subassembly
level
maintenance.
For convenience.
Operator's Manuals
are
published
separately
which
describe
all
operator controls and
functions. This
Service
Manual
is
subdivided
into
the following
sections,
each with
its
specific
purpose.
SECTION
1
-
INTRODUCTION,
presents the scope and content
of the manual and
provides the reader with
a general
description of the
printer.
SECTION
2
- THEORY
OF OPERATION,
provides
a description of each functional operation
in
the
printer, based
on
a
subassembly
level.
SECTION
3
-
PRINTER ASSEMBLIES:
REMOVAL/REPLACEMENT/ADJUSTMENT,
contains
a
functional
descrip-
tion,
removal/replacement/adjustment and maintenance procedures
for each
replaceable subassembly
in
the
printer.
SECTION
4
- MAINTENANCE,
includes preventive maintenance and
troubleshooting procedures,
as
well
as
schematic
and
wiring diagrams
of the
printer.
APPENDIX A -PARALLEL
INTERFACE
SPECIFICATIONS,
contains
detailed information
describing the standard
interface
timing
signals,
connectors and other
specifications.
APPENDIX
B
-SIGNAL GLOSSARY,
provides
a
table of
signal
names, by
mnemonic
code,
keyed
to the Line
Printer
Electronics
Board Schematic
Diagram.
NOTES
The TRS-80
Line
Printers are just
two
of
a series of Line Printers.
It
is
the intent of
this
manual
to provide
information only
for the
TRS-80
Line
Printers.
These
printers are basically
the same;
the
primary
difference
is
in
the
type of paper feed
assemblies.
The 26-1150
printer has
a
pinch
roller
assembly and
the
26-1152
has
a
tractor drive assembly.
Where
applicable,
a
procedure
or description pertaining
to either paper feed
mechanism
will
be
identified
by Catalog Number.
Part
Numbers
refer to the Manufacturer's
Part
Number, which may
be obtained
directly
from Radio
Shack's
National Parts Department.
Ill