Panasonic NN-8508 - Page 17

NN-8508, NN-8558
NN-8808, NN-8858
NN-8808P
3.
Replacement
of
the
digital
programmer
circuit
(D.P.C.)
and
membrane
key
board.
NOTE:
Be
sure
to
ground
any
static
electric
charge
built
up
on
your
body,
before
handling
the
D.P.C..
(A)
Disconnect
all
connectors
from
D.P.C..
(Fig.
19)
(B)
Disconnect
all
lead
wires
from
the
power
relay
B,
C
and
D.
(C)
Remove
1
screw
holding
the
escutcheon
base.
(Fig.
19)
(D}
Disconnect
flat
cable
of
membrane
switch
by
pushing
connector
lever
and
pull
it
(Fig.
20).
(E)
Remove
2
screws
holding
the
D.P.C..
(Fig.
20)
To replace membrane key board
(F)
Remove
escutcheon
bracket
from
escutcheon
base
by
freeing
4
catch hooks on the escutcheon base.
(G)
Peel
off
the
membrane
key
board
from
escutcheon
bracket.
NOTE
1:
The
membrane
key
board
is
attached
to
the
escutcheon
brack-
et
with
double
faced
adhesive
tape.
NOTE
2:
When
installing
new
membrane
key
board,
make
sure
that
the
surface
of
the
escutcheon
bracket
is
cleaned
sufficiently
so
that
any
problem
(shorted
contacts
or
uneven
surface)
can
be
avoided.
NOTE
3:
Make
sure
new
membrane
keyboard
is
aligned
to
the
left
and
lower
edges
of
the
escutcheon
bracket.
(Fig.
21)
4.
Replacement
of
the
low
voltage
transformer
and/or
Fig.
19
power
relays
(RY
A,
RY
B,
RY
C,
RY
D,
RY
E)
(Fig.
20)
NOTE:
Be
sure
to
ground
any
static
electric
charge
built
up
on
your
body
before
handling
the
D.P.C.
(A)
Using
solder
wick
or
a
desoldering
tool
and
30W
soldering
iron,
care-
fully
remove
all
solder
from
the
terminal
pins
of
the
low
voltage
trans-
former
or
power
relays
(RY
A,
RY
B,
RY
C,
RY
D,
RY
E).
CN
5
NOTE:
Do
not
use
a
soldering
iron
or
desoldering
tool
of
more
than
30
Low
watts
on
D.P.C.
board.
VOL
TAGE
(B)
With
ail
the
terminal
pins
cleaned
and
separated
from
D.P.C.
con-
TRANSFORMER
tacts,
remove
the
defective
transformer/power
relay
and
install
new
transformer/power
relay
making
sure
all
terminal
pins
are
inserted
completely.
Resolder
all
terminal
contacts
carefully.
Fig. 20
ESCUTCHEON
BRACKET
MEMBRANE
KEY BOARD
LEFT €DGE
LOWER EDGE
Fig. 21