Panasonic NN-8508 - Page 28

NN-8508, NN-8558
NN-8808, NN-8858
NN-8808P
(TROUBLE
5]
Troubles
related
to
Digital
Programmer
Circuit.
(Refer
to
schematic
diagram
on
page
39.)
SYMPTOM
CHECK
CAUSE
A.
|
No
display
when
oven
is
Voitage
of
L.V.T.
first
plugged
in
secondary
winding
sbomnal
OY.
L.V.
Transformer
NN-8808/8858/8808P
Voltage
of
IC1,
Pin
No.
\\
Abnormal
64
ZD1,
Q1
PIN
NO.
OF
L.V.T.
VOLTAGE
$1-S2
Approx.
AC
14V
Approx.
SV
(NOTE
1)
$3-S4
Approx.
AC
20V
voltage
of
IC1,
Pin
No.
Abnormal
$5-S6
Approx.
AC
3V
Normal
|
Approx.
5V
NN-8508/8558
PIN
NO.
OF
L.V.T.
VOLTAGE
Peel
Dna
$1-S2
Approx.
AC
20V
$3-S4
Approx.
AC
3V
B.
|
Abnormal!
Display:
1.
Dark
or
unclear
display
IC1,
DISPLAY
2.
Unnecessary
segment
;
turns
on
3.
Missing
segment
4.
Blurred
display
C.
Continuity
of
membrane
No
key-input
switch
(See
page
21)
senemne
Membrane
switch
Normal
D.
Abnormal!
Voltage of IC1, Pin No.
23
Normal | (NOTE 2)
Approx. 5V
No beep sound
NOTE 1: Refer to page 30.
Voltage of IC3, Pin No.
13
NOTE 2: When the pad is tapped,
meter
indicates
some
Normal
|
(NOTE
2)
voltage
for
a
moment.
ov
Abnormal