Sharp EL-5100S

3.
DISASSEMBLY
PROCEDURE
|. Remove two screws on the bottom cabinet.
_ Detach the bottom cabinet from the top Bolom more
cabinet as it is clasped to the top cabi-
net at the points, X, Y, and Z.
. Take batteries out (3 pes).
t.
4e Lo
. Remove nine screws at the points a ™ 1.
_
Detach
the
P.W.B.
from
the
top
cabinet
by
lifting
the
lower
part
of
the
P.W.B..
as
it
is
hooked
to
the
top
cabinet
at
the
upper
part
(LCD
side).
6. As soon as the P.W.B. was removed,
such as the key rubber and filter are
ready to remove.
7.
Now,
dismount
the
LCD
unit
by
releasing
the
hooks,
as
it is
hooked
to
the
P.W.B.
at
eight
locations
A
~
H.
8.
Then,
the
contact
rubbers
can
be
removed
when
the
LCD
unit
was
removed.
9.
As
the
LCD
is
held
to
the
angle
using
a
double-tack
adhesive
tape,
pour
in
a
small
amount
of
alcohol
into
the
contact
phase
between
the
LCD
and
the
angle.
This
will
make
separation
of
the
LCD
much
more
easier.
|
4. BLOCK DIAGRAM
a)
LCOD2401)
Segment
sgnal
Back
plate
ugnal
SC43328
tchip 1)
Decoder {t 7a~24e4
RAM
§C43125
(Chip 2)
Decoder (9a~ 16e)
RAM
cays
(Chip 31
Decoder ¢( la~ Be?
RAM
Algebras ctpres {a ss IM}
son in COMP mode
Alecbrasc expres
son in AER mode
@ Key Section
Key
signals
are
sent
to
the
LSI
as
key
signals
Ki,
~
Kijs.
while
key
strobe‘signals
are
sent
from
the
SC43151 as key strobe signals Sy ~ Si6.
e Arithmetic Logic Section
All
the
arithmetic
operations
are
carried
out
in
the
SC43150
on
the
basis
of
key
signals
Ki;
~
Kijg.
However.
some
part
of
the
IK
RAM
within
the
display
chip
(SC43125)
is
used
for
the
memory
of
the
SC43150,
exchanging
the
data
corresponding
to
the
address
bus
(B,
~
Bs)
via
Dip,
~
Dog.
® Display Section
When
the
signal
Chip
Enable
is
in
high
state,
the
display
data
is
received
into
the
designated
address
(B,
~
Bg)
of
the
SC43125
via
the
lines
Dig,
~
Dioa.
Though
the
display
data
is
decoded
into
one
of
signals
la
~
24e
by
the
decoder
in
the
SC43125,
it
is
then
controlled
by
the
signal
HA
for
synchronizing
with
the
back
plate
signal.
If
the
signal
Disp
is
in
high
state
(out
of
arithmetic
operation),
the
decoded
signal
la
~
24e
is
sent
to
the
LCD
as
a
segment
signal
so
that
segments
are
lit
corresponding
to
the
back
plate
signal
H,
~
H,
directly
received
from
the
SC43151
.
7