Service manual
LSI's and IC's used in
the
MZ-80K
are semiconductor integrated
circuits
whose basic element
is
MOS FET.
The
IC's,
so
poor
in static
electricity
or
leakage
current
from
soldering
tool,
are
liable
to
suffer breakdown.
It
is
essential therefore
to
read the
following
instructions
carefully
and
handle them
properly.
Cl)
Ground
your
body
before handling LSI's
or
IC's.
Grounding
must
be
made
through
a resistor
of
serveral Mohms
for
avoiding danger.
Note
that
if
possible,
you
wear
cotton
gloves and
working
clothes,
but
not
chemical
fiber
ones easily
charged
with
static
electricity.
Ground
on
water
pipe
or
connect·
to
ground
terminal.
Electroconductive
LS I storage
sponge
(Mos-Mat),
or
grounded
aluminum
foil
or
the
like
Method
of
working
and
handling
LSI:s
and
IC's
(2)
When
putting
LSl's on a
work
bench
during
repair,
lay grounded
aluminum
foil
or
the
like
superior in
electric
conductivity
under them.
(~Use
a grounded soldering
tool
free
from
leakage
current. Even
if
current
leaks
out
to
the
tip
of
soldering
tool,
gate insulation layer
is
protected
by
the
action
of
protective doide. However,
too
much
leakage current,
which
is
caused
by
the
tip
in
direct.
contact
with
power supply,
for
instance,
may break the protective diode itself. Therefore,
never fail
to
use
a soldering
tool
free
from
leakage
current.
A low-voltage soldering
tool
(6V,
12W)
is
optimal.
@ When inserting LSI's
or
IC's
into
the
printed
wiring
board, avoid
touching
their
pins
directly,
but
hold
their
black plastic packages.
-3-
@ When inserting LSI's or IC.s,
don't
mistake
their
inserting
direction
unconditionally.
Reverse
insertion damages them.
® When storing and
transporting
an
LSI
or
IC
separately,
wrap
it
with
aluminum
foil
or
insert
into
electroconductive sponge (Mos-Mat)
to
maintain
terminals at the
same
potential.
(])
Storage temperature
of
LSI
is
-20
to
+70°C, and
that
of
IC
-40
to
+125°C.
It
is
recommended,
however,
to
store
them
at a temperature near
room
temperature
if
possible.
Avoid
storing
them
on
a place
extremely
hjh
or
low
in
humidity.
®
Be
careful
to
refrain
from
giving
an
unreasonable
mechanical
impact
to
LSI's
or
IC's,
or
from
giving
an
unreasonable
force
to
lead wires.
®
Turn
off
the
power
switch
without
fail before
detaching
LSI's
or
IC's
from
the
main
body.
@ Solder LSI's
or
IC's in a
short
time
so
as
to
prevent
an
unseasonable thermal
impact
to
them.