Panasonic NE-992 User manual

Service
Mantua.
NE-992, NE-993
NE-972
For United Kingdom
For NAAFI
DIMENS:ONG eee! || | DIMENSIONS
NE-992,
NE-993
NE-972
Power
Requirement:
=
|
2&8
KW
(11.0
Apr
Maximum
Required
Power
(Microwave
&
Grill
Heater)
(Convection
Heater
&
Grill
Heater)
1.2 KW (5.6 A):+:: Microwave
1.2 KW Convection Heater
1.5 kW Grill Heater
Pepi
|
80
WF
Mra
Poe
Oscillation
Frequency
:
2,450
MHz
568 mW) X 495 rm (D) % 386 men (A
pW:
Ci
Specifications subject to change without notice.
-
j j
ing
Co.,
Ltd.
Panasonic
ee

WARNING
* This product should be serviced only by trained, qualified personnel. As for the oven lamp, it is replaceable by the
users.
* This service manual covers products for following markets.
When troubleshooting or replacing parts, please refer to the country identifications shown below for your applic-
able product specification.
For United Kingdom
For NAAFI
CONTENTS
OUTLINE DIAGRAM & CONTROL PANEL
NE-992/NE-993
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SCHEMATIC DIAGRAM
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9
DESCRIPTION
OF
OPERATING
SEQUENCE
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10
AUTO
SENSOR
EXPLANATION,
K
FACTORS
AND
POWER
LEVELS:
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CAUTIONS TO BE OBSERVED WHEN TROUBLESHOOTING: :::----- Jagdine Seahees WgdesvaaUaduetcdea wed decease dovae det asses vatea sedans coedeue evensersgseeer vane Seobesgs 18
DISASSEMBLY AND PARTS REPLACEMENT PROCEDURE: ::11rr:cstseeertseerereetetteeeeenteeeectnseeeereeeertseeeeen nines esennenegaaeeesrnnneeerenernens sannnnes 19
COMPONENT TEST PROCEDURE <vrreeeesrececrteeseeeseesereeeceeeeeeeaeeeeeeneeeseneneeeerseeeesnseeeenisaeessseeteesesceseseeanerecereneeeeeeesenenreeeeesnn ceeees 23
MEASUREMENTS AND ADJUSTMENTS ‘crccerescccteersseesesteteseeeeeeeenessseeennneesenseeeesssseeserseeeeenseesensasasesensteeeersaneeecaeeeensneeecererteis cenernes 25
TROUBLESHOOTING GUIDEs +s ceesccestresteereeerseeeseetseeseeeneeneeeneens teen senna ee teens eeneeen eee eeeeenee sete ee ene ee eee teeeeeeeneecneaeeeeeeeneesneeeteeeie oeetse 26
DIGITAL PROGRAMMER CIRCUIT TEST PROCEDURE
NE-992/NE-QO3-+coecccceereeeeseeteseeesseceesseecsseeeseeeeessenseseneeeeessseessseeeneeeenieeestecenseeeseeensseeeneeeeessaeeesaeesaeeessaeeeeecaesesennegenseneese #aeeeees 33
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EXPLODED
VIEW
AND
PARTS
LIST
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50

NE-972
OUTLINE DIAGRAM & CONTROL PANEL (NE-992/NE-993)
Outline Diagram jini
@ Oven Window
@ Door Safety Lock System
Before any cooking function can begin, oven door
must be securely shut.
@ Oven Light
Will turn on whenever the door is opened or during
cooking. :
@ Oven Light Cover
Allows easy access to replace the oven light.
© Oven Air Vents
Never block air vents during cooking.
© Control Panel
See below.
@ Ceramic Tray
Must be placed in the oven before cooking.
Roller Ring
Must be placed in the oven before cooking.
@© Nameplate
Control Panel wri NEE
@ Controls with Auto Count-Up Feature
@ Cyclic Defrost Pad
@ Grill Pad
@ Auto Sensor
Cooking Pad
@® Adjust to
Taste Pad
@ Auto Weight
Defrost Pad
® Auto Weight
Combination Pad
@ Kg/ib Convert Pad
Display Window
Time Pads
Power Pad
Combination Pad
Dual-Shelf Pad
Convection
Temperature Pad
Cooking Guide
1kg/1 Ib Pad
0.1 kg/1.0 oz Pad
Start Pad
Door Opener Button

NE-972
OUTLINE DIAGRAM & CONTROL PANEL (NE-972)
Outline
Diagram
writin
cient
@ Oven Window
@ Door Safety Lock System
Before any cooking function can begin, oven door
must be securely shut.
@ Oven Light
Will turn on whenever the door is opened or during
cooking.
@ Oven Light Cover
Allows easy access to replace the oven light.
© Oven Air Vents
Never block air vents during cooking.
© Control Panel
See below.
@ Ceramic Tray
Must be placed in the oven before cooking.
Roller Ring
Must be placed in the oven before cooking.
@ Nameplate
Control
Panel
witisuiieiaveiinieinininieaeiae
TEETER
@ Controls with Auto Count-Up Feature
Display Window
Time Pads
Power Pad
@
Cyclic
Defrost
Pad
Combination
Pad
Grill
Pad
Dual-Shelf
Pad
Convection
Temperature
Pad
1: Best (Rare} 5. Lamb (W Done)
®
Auto
Weight
2:
Beet
(Medium)
6
-
Pork
Gammon
Combination
Pad
3
eet
(W
Dona)
7:
Chacon
4: Lammy (Medaumn) 8 + Turkary
Cooking Guide
ig 1kg/1 Ib Pad
® Kg/lb Convert Pad 0.1 kg/1.0 oz Pad
@ Clock Pad
@®
Stop/Cancel
Pad
216
Start
Pad
Door Opener Button

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NE-972
OPERATION GUIDE FOR NE-992 & NE-993
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NE-972
OPERATION GUIDE FOR NE-972
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a
ACCESSORIES
Accessories wiiiiiitiiiiiimiiminiminiaianitii
Accessories and Use
CO
=
=
Drip Tray-Grill Pan Splash Guard Ceramic Tray
(ANE0603Z705P) (ANE0648Z70BP) (ANE0601Z70BP)
Splash Guard: Ceramic Tray:
Use with the Drip pan. Splash Oven should not be operated
Guard helps prevent splashing. without the Ceramic Tray.
High-Rack Baking Tray Handle
(ANE0602Z70BP) (ANE0641Z70BP) (ANE0709Z70BP) (ANE0604-F 20)
Followings are the recommendabie usages:
Low-Rack
Drip Tray-Grill
Pan
High-Rack
Drip Tray-Grill Pan Low-Rack
CONVECTION/ DUAL-SHELF COOKING GRILL/GRILL COMBINATION
CONVECTION COMBINATION
Do not use the following accessory combination Do not use the following except during convection
in any case:
Drip Tray-Grill Pan
High-Rack
Further instruction will be given in the instruction section of applicable cookbook.

SCHEMATIC DIAGRAM (NE-992, NE-993 BPQ/PPQ)
SCHEMATIC DIAGRAM
tH — —
YELLOW/GREEN
WIRING DIAGRAM
POWER AELAY 3
(UPPER)
|
NNN
Hf
NOISE FILTER
VARISTOR
SUAGE ABSOABEA
Note: *Door is closed.
*Unit is not operated yet.
THERMAL
CUTOUT (OVEN)
GRILL HEATER
CONVECTION HEATEA
OVEN LAMP
240V 25W
TURN TABLE
MOTOR
RELAY 7
SHORT SWITCH
AHooonad 1000000000
RELAY 3
SAFETY SWITCH 8 2aov *
bass
HUMIDITY SAFETY SWITCH A
SENSOR HEATER {DOOR SIGNAL SWITCH)
LOW VOLTAGE
TRANSFORMER
TAI. AY.7 A
DIGITAL PROGRAMMER CIRCUIT
(F=4,49MH2)
Caen em ertnslrimnnnenmnrrnrenremernemennarer eres are tices TI seme” ame mmm noe eee nail
Note: *When replacing, check the lead wire colour as shown.
*Colours shown by ( ) indicate colours of lead
wire connector housing. "4
POWER RELAY 2
(CENTER)
DIGITAL PROGRAMMER CIRCUIT
POWEA RELAY S
{LOWER)
SHORT SWITCH
: 8/BL
SAFETY SWITCH B
HUMIDITY SENSOR
COL OUR
po once
Pe [oom |
cco
aco
Pep]
acce
(S-Z73 P)
Fig. 1A

|__NE-972
SCHEMATIC DIAGRAM (NE-972 BPQ/PPQ)
SCHEMATIC
DIAGRAM
Note:
*Door
is
closed.
“Unit
is
not
operated
yet.
THERMAL
NOISE_FILTER CUTOUT (OVEN) re 5
'
he ms
IELAY 6
———1
OVEN LAMP
240V 25W
'
LIAGE TRANSFORMER =O S
VARISTOR
GRILL HEATER
CONVECTION HEATER
FAN MOTOR | A
CONVECTION
SHORT SWITCH
THERMAL
CUTOUT
{MAGNE TRON)
FILTER COIL 0,2mHx2
RELAY 3
SURGE ABSORBER
Fear |
00066000600000090006.
YELLOW/GREEN
RELAY 2
SAFETY SWITCH A
(DOOR SIGNAL SWITCH)
LOW VOLTAGE
TRANSFORMER
TEMPERATURE
DIGITAL PROGRAMMER CIACUIT
(F=500KH2)
-_
SS
WIRING
DIAGRAM
Note:
“When
replacing,
check
the
lead
wire
colour
as
shown.
*Colours shown by ( ) indicate colours of lead
wire connector housing.
SYMBOL COLOUR
SHORT
SWITCH
|
an
|
BROWN
ce
. [ee
aa
SAFETY SWITCH A
W/W (G)
POWER RELAY 2 POWER RELAY 3 POWER RELAY 5
(LOWER LEFT) (LOWER RIGHT) (UPPER)
LIGHT
BLUE
BLACK
DIGITAL PROGRAMMER CIRCUIT SAFETY SWITCH B
(S-R7BP)

NE-9/2 |
DESCRIPTION OF OPERATING SEQUENCE
1, Variable power cooking control
The coil of power relay (5) is energized intermittently by the digital Power setting | Output Power
programmer circuit, when the oven is set at any power selection ex-
cept for High power position. The digital programmer circuit controls
the ON-OFF time of power relay (5) contacts in order to vary the out- ;
put power of the microwave oven from “Warm” to “High” power. One Ly | 6OOW (22/22)
complete ON and OFF cycle of power relay (5) is 22 seconds.
The relation between indications on the control panel and the output ‘fi
On-Off Time of
Power Relay (5)
of the microwave oven is as shown in Fig. 2A. Medium ™ | 480W (19/22)
NOTE: The ON/OFF time ratio does not correspond with the percentage
of microwave power since approximately 2 seconds are required 45 Gad. 237-566
for heating of magnetron filament Co | 360W (15/22)
2. Cyclic defrost
When defrost power and defrosting time is selected and Start pad is
touched: 180W (9/22)
(A) The digital programmer circuit (DPC) divides the total defrosting time
into 8 intervals of alternating defrosting power and standing periods.
(See Fig. 2B) 70W (4/22)
(B) During defrosting power period, power relay (5) is energized for 10
seconds and de-energized for 12 seconds by DPC. (See Fig. 2C)
{C) During Standing periods, power relay (5) is always open resulting in Approx. 120W| Refer to description of cyclic defrost.
no microwave power.
NOTE: Defrost time selected is converted into seconds by the DPC but
display will show selected time in minutes and seconds as prog-
rammed. The total number of seconds is divided into 8 time
periods. The remainder (seconds not equally divisible by 8) are
added to the last standing time period.
Example # 1: If defrosting time is selected for 2 minutes 56 seconds,
each operating period will be as follows : (See Fig. 2D)
2 minutes 56 seconds = 176 seconds 176/8 =
Example # 2: If defrosting time is selected for 5 minutes, each operating DEFROST DEFROST DEFROST
period will be as follows : (See Fig. 2E)
5 minutes = 300 seconds
300/8 = 37 and remainder is 4 seconds.
The 4 seconds is added to the last time period.
NOTE: When defrosting time is selected for not more than 7 seconds, Fig. 2B
the power relay (5) will not be energized at all. :
Fig. 2A
TOTAL DEFROSTING TIME (T)
ONE DEFROSTING PERIOD
2 MIN..56 SEC. (176 SEC.)
ONE ONE ONE
elie STANDING DEFROSTING
(228) (22S)
}OSEC
,
12SEC.
|
Se
asec
}0SEC
,
128eC
_|
Fig. 2D
5 MIN. (300 SEC}
1ST 2ND
ane woe NG STANONG
)
(415)
ALL OFF ALL OF
Fig. 2E

| NE-972
3. Auto weight defrost control( 73 )
Consists of the following pads:
+ Auto Weight Defrost Pad( %% )
* kg/Ib convert Pad
« Weight Pads
¢ Start Pad
When
the
Auto
Weight
Control,
Defrost
feature
is
selected
and
the
Start
Pad
is
tapped:
(A)
The
digital
programmer
circuit
determines
the
power
levels
and
de-
frosting
time
to
compiete
defrosting
and
indicates
the
operating
state
in
the
display
window.
Fig.
3
shows
the
defrosting
times
for
respective
weights
by
cate-
gories.
(B)
When
defrosting
time
in
the
display
window
has
elapsed,
the
oven
turns
off
automatically
by
the
controlled
signal
from
the
digital
prog-
rammer
circuit.
Auto
Weight
Defrost
(
*3
)
(For
NE-992,
NE-993
only)
TOTAL DEFROSTING TIME
SELECTED
CATEGORY
1
CATEGORY
2
CATEGORY
3
CATEGORY
4
2.0
kg
1
hour
23
min.
1
hour
30
min.
35
min.
00
sec.
Ee
1
4.0
kg
2
hour
46
min.
19
min.
12
sec.
20
min.
48
sec.
8
min.
00
sec.
38
min.
24
sec.
41
min.
36
sec.
16
min.
00
sec.
t
hour
02
min.
|
__24
min.
00
sec.
1
hour
16
min.
1
hour
36
min.
1
hour
44
min.
40
min.
00
sec.
eT
TS
Eo
oA
_
eee
nl
Fig. 3
WEIGHT
DISPLAY
2 hour 33 min.
2 hour 52 min.
3 hour 12 min.
3 hour 31 min.
11 LB 11 tb 00 oz

NE-972 |
4. Convection cooking control ( )
The digital programmer circuit controls the ON-OFF time of convec-
tion and grill heaters which are located at rear and top of oven cavity
respectively in order to control oven cavity temperature.
Normal Convection Cooking
(A) After the start pad is tapped with the desired normal convection prog-
ramme set, an 18V DC signal comes out of the digital programmer
circuit and is applied to the coils of power relays 2 and 3.
(B) When power relays 2 and 3 energize, power source voltage (240V
AC) is applied to both convection and grill heaters and oven tempera-
ture starts increasing.
(C) When the oven temperature reaches the set temperature, the digital
programmer circuit senses the temperature through oven temp sen-
sor and stops supplying an 18V DC signal to the power relays 2 and 3
resulting in both convection and grill heaters to turn off.
After the heaters turn off, the oven temperature will continue increas-
ing a while then decrease as shown in Fig. 4.
(D) When the oven temperature drops below the set temperature, the
digital programmer circuit senses the oven temperature and starts
supplying an 18V DC signal to the coils of power relays 2 and 3 again.
Note that grill heater (power relay 2) tums on and off alternatively at
predetermined duty cycle (7 sec ON, 15 sec OFF) until oven temper-
ature reaches set temperature again by the signal from digital prog-
rammer circuit. (Fig. 4)
Conv. Heater
(Power Relay 3)
Grill Heater
(Power Relay 2)
Grill Heater
(Power Relay 2)
oO
z
xz
ro)
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ra)
—_
=
=
a
o
=
oO
z
x
ro)
6
ca)
)
=
>
a
Microwave
Oven Lamp
(Power Relay 6)
Turntable
Fan Motor
Dual Shelves Convection Cooking ( )
When the start pad is tapped with dual shelves convection cooking fea-
ture selected;
(A) The digital programmer circuit generates the 18V DC of 20 sec ON, 2
sec OFF signats for convection heater (power relay 3) and continued
High signal for grill heater (power relay 2) as shown in Fig. 4 so that
both heaters turn on to increase oven cavity temperature.
(B) When the oven temperature reaches set temperature, the digital
programmer circuit stops supplying the 18V DC signals to turn both
heaters off.
(C) When the oven temperature drops below the set temperature, the
digital programmer circuit starts to supply the 18V DC signals again
but at different duty ratio as shown in Fig. 4.
NOTE: See Fig. 4 for operating sequences of microwave, tumtable, fan
and convection fan motors during convection cooking mode.
(Triac) Ee pee il ON (slow) i
Convection Motor
ac OC [Rs
Fig. 4

NE-972
5. Grill cooking control ( (*] )
The
grill
cooking
control
functions
very
similarly
to
convection
cooking
control
except
the
timing
of
applicable
heaters
ON
OFF
periods.
(A)
After
the
start
pad
is
tapped
with
the
desired
grill
programme
set,
the
digital
programmer
circuit
generates
the
18V
DC
signals
and
supplies
to
power
relays
2
and
3
so
that
both
power
relays
energize
to
turn
on
the
grill
and
convection
heaters.
(B)
When
both
heaters
turn
on,
the
oven
temperature
rapidly
increases
and
when
it
reaches
240°C,
the
digital
programmer
circuit
stops
sup-
plying
an
18V
DC
to
power
relay
3
coil
but
continues
to
supply
to
power
relay
2.
(C)
The
digital
programmer
circuit
continues
to
supply
an
18V
DC
to
pow-
er
relay
2
for
a
period
of
25
minutes
and
when
25
minutes
have
elapsed,
the
digital
programmer
circuit
starts
cycling
to
supply
an
18V
DC
at
a
rate
of
one
minute
ON
and
one
minute
OFF
until
cooking
programme
completes.
The convection heater remains off through out the rest of cooking
cycle.
GRILL COOKING ( &*) )
START _ 250°C
, Aa ce
OVEN TEMP
Grill Heater
(Power Relay 2)
Convection Heater
(Power Relay 3)
Microwave
(Power Relay 5)
Oven Lamp
(Power Relay 6)
Turntable
Fan Motor
(Triac)
Convection Motor
(Power Relay 7)

E-¥Y¥?, NE-9¥o
E-972
6.
Combination
cooking
control
(
4,
2
)
Combination
cooking
is
accomplished
by
microwave
and
convection
cooking
being
done
simuitaneously
during
combination
cycles.
When
combination
categories
1,
2,
3
and
4
are
selected;
(A)
The
digital
programmer
circuit
generates
the
power
relays
2,
3
and
5
control
signais
at
timing
shown
in
Fig.
6B.
The
power
relay
5
(microwave)
remains
off
until
oven
temperature
reaches
predetermined
temperature
which
varies
by
each
category
number
as
shown
in
Fig.
6A.
(B)
When
the
oven
temperature
reaches
the
predetermined
temperature,
MICROWAVE POWER
COMBINATION
CATEGORY
aan
ovey
DUTY
ON TIME | POWER
6/22 SEC
the
digital
programmer
circuit
stops
supplying
power
relays
2
and
3
MICROWAVE
&
10/22
SEC
control
signals
resulting
in
both
grill
and
convection
heaters
to
turn
off
CONVECTION
and
starts
supplying
power
relay
5
contro!
signal
so
that
microwave
COMBINATION
activity
starts
at
predetermined
duty
ratio
as
shown
in
Fig.
6A.
160
W
180
°C
The
microwave
activity
continues
to
cycle
until
entire
cooking
prog-
ramme
is
completed.
(C)
When
the
oven
temperature
drops
below
the
predetermined
temper-
ature,
the
digital
programmer
circuit
generates
power
relay
2
and
3
contro!
signals
again
at
the
timing
predetermined.
9/22 SEC | 220W 180 °C
15/22 SEC] 380W | 4PPFOX.
NOTE:
The
power
relays
2,
3
and
5
never
tum
on
at
the
same
time.
MICROWAVE
&
250
‘C
Elther
power
relay
should
be
always
off
so
that
input
current
al-
GRILL
ways
remains
within
allowable
household
current
(13A).
COMBINATION
approx.
7/22 SEC | 160 W 250 ‘C
COMBINATION
COOKING
(1.
Microwave
&
Convection
Combination
—
Category
1,
2,
3,
4)
OVEN TEMP
Grill Heater
(Power Relay 2)
Convection
Heater
ON
(Power
Relay
3)
YYW)
Microwave
(Power Relay 5)
Oven Lamp
(Power Relay 6)
Turntable
Fan Motor
(Triac)
Convection Motor
(Power Relay 7)
Fig. 6B
|
1

When combination category 5 and 6 are selected;
(A)
The
digital
programmer
functions
exactly
the
same
as
when
category
1
through
4
are
selected
until
oven
temperature
reaches
240C.
(B)
When
oven
temperature
reaches
240°,
the
digital
programmer
cir-
cuit
stops
supplying
control
signal
for
power
relay
3
but
continues
to
supply
to
power
relay
2
and
starts
supplying
the
control
signal
for
power
relay
5
at
the
timing
shown
in
Fig.
7.
The
power
relay
3
remains
off
through
out
the
rest
of
entire
cooking
cycle.
(C)
After
oven
temperature
reaches
240°,
the
microwave
activity
con-
tinues
in
the
rest
of
entire
cooking
cycle.
NOTE
1:
The
power
relays
2,
3
and
5
never
turn
on
at
the
same
time.
Either
power
relay
should
be
always
off
so
that
input
current
al-
ways
remains
within
allowable
household
current
(1A).
NOTE
2:
Note
that
the
heater
may
not
be
on
during
a
heater
on
period
if
the
predetermined
oven
temperature
has
been
reached.
NOTE
3:
Fig.
6A
shows
the
predetermined
microwave
power
and
oven
temperature
for
each
category
pad.
Each
programme
is
pre-
programmed
in
the
microprocessor.
NOTE
4:
The
fan
motor
speed
differs
depending
on
the
category
pads.
When
categories
1
through
4
are
selected,
the
fan
rotates
at
slower
speed
while
category
5
and
6
are
selected
it
runs
at
full
speed.
COMBINATION COOKING (2. Microwave & Grill Combination — Category 5, 6)
OVEN TEMP
(Powe ey 2) MMU,
Convection Heater 0
(Power
Relay
3)
Microwave OFF OFF
(Power Relay 5)
Oven Lamp
(Power Relay 6)
Turntable
Fan Motor
(Triac)
Convection Motor
(Power Relay 7)
NE-972
“

NE-972
7. Auto weight combination cooking control ( eS )
Consists of following pads:
* Auto Weight Control, Combination Pad
* kg/lb Convert Pad
« Weight Pads
* Start Pad
When the Auto Weight Control, Combination Cooking feature is
selected by tapping the appropriate key pads and Start pad is
tapped.
(A) The digital programmer circuit determines the power jevel, oven
temperature and combination cooking time to complete combination
cooking and indicates the operating state in the display window.
Fig. 8 shows the combination cooking times for respective weights by
categories.
(B) When the combination cooking time in the display window has
elapsed, the oven turns off automatically by the controlled signal from
the digital programmer circuit.
NOTE: Refer to cooking pattern of “Microwave & Convection Combina-
tion/Fig. 6B.” for Auto Weight Combination Cooking.
AUTO WEIGHT COMBINATION
WEIGHT TOTAL COMBINATION COOKING TIME
SELECTED] CATEGORY 1 | CATEGORY 2 | CATEGORY 3 | CATEGORY 4 | CATEGORY 5 | CATEGORY 6 | CATEGORY 7 ; CATEGORY 8
30 min. 00 sec. ; 45 min. 00 sec. ; 38 min. 20 sec. 43 min. 20 sec. . 18 min. 20 sec.
1k9 | (29 min. 45 sec.) | 2° MIP 00 Se. | (44 min. 55 sec.) (37 min. 55 sec) | (43 min. 10 sec) | 297. 20 sec. | (48 min. 05 sec.)
1 hour 00 min. ; 1 hour 30 min. ; 1 hour 16 min. , : 36 min. 40 sec.
2kg (59 min. 30 sec.) 1 hour 10 min. (1 hour 29 min,) 1 hour 26 min. 46 min. 40 sec. (36 min. 10 sec.)
4 hour 30 min. : ; 2 hour 15 min. , 1 hour 55 min. 2 hour 10 min. A 55 min. 00 sec.
3 kg (1 hour 29 min.) 1 hour 45 min. (2 hour 14 min.) 1 hour 45 min. (1 hour 53 min.) (2 hour 09 min.) 1 hour 10 min. (54 min. 15 sec.)
(1 hour 12 min.)
(1 hour 30 min.)
1LB 13 min. 36 sec. | 16 min. 00 sec. | 20 min. 32 sec. | 16min. 00 sec. | 17 min. 20sec. | 19 min. 44 sec.
2B 27 min. 12 sec. | 32 min. 00 sec. | 41 min. 04sec. | 32 min..00 sec. 21 min. 20 sec. 16 min. 32 sec.
3 LB 40 min. 48 sec. 48 min. 00 sec. | 52min. 00 sec. | 59min. 12 sec. | 32min. 00 sec. | 24 min. 48 sec.
41B §4 min. 24 sec. 4 hour 04 min. 1 hour 22 min. 1 hour 04 min. 42 min. 40 sec.
5 LB 1 hour 08 min. 1 hour 20 min. 1 hour 42 min. 1 hour 38 min. 53 min. 20 sec. 41 min. 20 sec.
1 hour 58 min. 1 hour 04 min.
1 hour 52 min. 2 hour 01 min. 2 hour 18 min. 1 hour 14 min.
a ee
a os
Fig. 8
1 hour 36 min. 2 hour 03 min.
1 hour 52 min. 2 hour 23 min.
ce ee
NOTE: The cooking times shown in the bracket ( ) of CATEGORY 1, 3, 5, 6, 8 are applicable to only for model NE-972.

NE-972
AUTO SENSOR EXPLANATION, K FACTORS AND POWER LEVELS
( For NE-992, NE-993 only)
1. Auto sensor cooking
Auto sensor cooking is a revolutionary way to cook by microwave with-
out ‘setting a power level or selecting a time.
All that is necessary is to select an Auto Sensor Program before start-
ing to cook.
Understanding of Auto Sensor Cooking
As a food cooks, a certain amount of steam is produced. If the food is
covered, this steam builds up and eventually escapes from the con-
tainer. In Auto Sensor Cooking, a carefully designed instrument, cal-
led the humidity sensor element, senses this escape of steam. Then,
based upon the Auto Sensor Program selected, the unit will automati-
cally determine the correct power level and the proper length of time
it will take to cook the food.
NOTE: Auto Sensor Cooking is successful with the foods and recipes
found in the Auto Sensor Cooking Guide. Because of the vast
differences in food composition, items not mentioned in the
Cooking Guide should be prepared in the microwave oven using
power select and time features. Please consult Variable Power
Microwave Cookbook for procedures.
2. Auto sensor cooking process
Explanation of the Auto Sensor Cooking process (See Fig. 9A)
1) The shaded columns in the graph indicate when the humidity sensor
heater is on.
2) During the first 60 second period there is no microwave activity, and
when calculating the T2 time by using the formula below make sure
this 60 seconds is subtracted from the T1 time. In other words T1 time
starts at the end of the 60 second period. (This 60 second period is
needed for the sensor element to stabilize and balance itself to the
humidity present before microwave activity starts.)
3) T1 time::-The total amount of time it takes the microwave oven to
switch to T2 time after the 60 second period. During this time one of
the Auto Sensor programs (A1-A8) will be shown in display.
4) T2 time---When the steam escapes from the cooking container
placed in the oven, the humidity sensor detects it and the microp-
rocessor calculates the balance of cooking time. This T2 time is then
shown in the display and begins counting down.
NOTE: tf T1 time is over 60 minutes, oven stops automatically and “FF
FF” appears in display window.
Balance of cooking time (T2 time)
The balance of cooking time which is called T2 time, can be calcu-
lated by the following formula.
T2 time (in sec.) =T1 time X K tactor
NOTE: When calculating T2 time, the last digit of T1 time in seconds is
cut away. For instance, If the T1 time is 76 seconds, the T2 time
will be:
T2=70XK
Remember, the T1 time starts after the 60 second period. The
coefficient K is programmed into the microprocessor memory
and they are listed in the following tables along with the P1 and
P2 powers. (See Fig. 9B)
NOTE: When “More” or “Less” pad is selected, the K factor varies as
shown in Fig. 9B resulting in T2 time to be increased or de-
creased.
Some examples of calculating the T2 time
Example 1: tf the T1 time is measured to be 2 minutes and 45 seconds
after the 60 second period, and the Auto program selected
is £4 (COOK) AS:
w2=T1i XK
= 2 min. and 45 sec. X 2.0
= 160 sec. X 2.0
= 320 sec.
= § min. and 20 sec.
sali
(COOK), & (FROZEN - COOK)
Magnetron Steam
detected
v
118 sec,!
1 ' 1
t
|
{
!
1
|
i
|
I
P1 power P2 power
‘
\
pei]
#3 (FROZEN — COOK)
P1 P2 K factor
Power Power Standard | More | Less
£4 (Cook)
Pas mor [mn [20 | en 26 | sm 6
Pas [mor | veo [1s | wma | eee 2
Par [mor [tow [eo [ rn a8 | a
Fig. 9B
Example 2: If the T1 time is measured to be 15 minutes and 30 seconds
after the 60 second period, and the Auto program selected
is 24 (FROZEN-COOK) A2:
T2=Ti XK
= 15 min. and 30 sec. X 0.7
= 930 sec. X 0.7
= 651 sec.
= 10 min. and 51 sec.
NOTE: if using a calculator please remember the calculator rounds off in
decimal numbers, so the T2 time will come out slightly different
than If seconds are changed back to minutes by regular long divi-
sion. When using a calculator, simply multiply the tenths by 60 to
get the correct number of seconds.
For instance take the T2 time in seconds from Example 2 above.
Using the calculator divide 60 into 651 and the quotient will be
10.85. Then multiply 0.85 by 60 and the product will be 51
seconds.
|
|

CAUTIONS
TO
BE
OBSERVED
WHEN
TROUBLESHOOTING
Unlike
many
other
appliances,
the
microwave
oven
is
high-voltage,
high-
current
equipment.
Though
it
is
free
from
danger
in
ordinary
use,
extreme
care
should
be
taken
during
repair.
CAUTION
Servicemen
should
remove
their
watches
whenever
working
close
to
or
replacing
the
magnetron.
1. Check the grounding
Do
not
operate
on
a
2-wire
extension
cord.
The
microwave
oven
is
designed
to
be
used
when
grounded.
It
is
imperative,
therefore,
to
make
sure
it
is
grounded
properly
before
beginning
repair
work.
2.
Warning
about
the
electric
charge
in
the
high
voltage
capacitor
(Fig.
10)
For
about
30
seconds
after
the
oven
is
turned
off,
an
electric
charge
remains
in
the
high
voltage
capacitor.
When
replacing
or
checking
parts,
turn
the
oven
off,
wait
30
seconds
and
short
the
terminal
of
the
high
voltage
capacitor
(terminal
of
lead
wire
from
diode)
to
chassis
ground
with
an
insulated
jumper
lead
wire
to
discharge.
WARNING
There
is
high-voltage
present,
with
high-current
capabilities
in
the
circuits
of
the
high
voltage
winding
and
filament
winding
of
the
high
voltage
transformer.
It
is
extremely
dangerous
to
work
on
or
near
these
circuits
with
oven
energized.
DO
NOT
measure
the
voltage
in
the
high
voltage
cir-
cuit
including
filament
voltage
of
magnetron.
WARNING
Never
touch
any
circuit
wiring
with
your
hand
nor
even
with
an
insulated
tool
during
operation.
3.
When
parts
must
be
replaced,
remove
the
power
plug
from
the
outlet.
4.
Avoid
inserting
nails,
wire,
etc.
through
any
holes
in
the
unit
during
operation.
Never
insert
a
wire,
nail
or
any
other
metal
objects
through
the
lamp
holes
on
the
cavity
or
any
other
holes
or
gaps,
because
such
objects
may
work
as
an
antenna
and
cause
microwave
leakage.
5. Confirm after repair
(A)
After
repair
or
replacement
of
parts,
make
sure
that
the
screws
of
the
oven,
etc.
are
neither
loose
nor
missing.
Microwaves
might
leak
if
screws
are
not
properly
tightened.
(B)
Make
sure
that
all
electrical
connections
are
tight
before
inserting
the
plug
into
the
wall
outlet.
6. Replacement of the power cable.
When
replacing
the
power
cable,
the
cord
bushing
and
the
cord
bushing
mounting
plate
should
be
replaced
together.
HIGH VOLTAGE
CAPACI TOR
INSULATED
HANDLE
SCREWDRIVER
CHASSIS
DIODE
ASSEMBLY
Touch chassis side first then short to the high voltage capacitor
terminal.

| NE-972
DISASSEMBLY
AND
PARTS
REPLACEMENT
PROCEDURE
1.
Replacement
of
the
magnetron
(See
Fig.
11A
&
11B)
CAUTION
Servicemen
should
remove
their
watches
whenever
working
close
to
or
replacing
the
magnetron.
(A)
Discharge
the
high
voltage
capacitor.
(See
page
18.)
(B)
Remove
2
screws
holding
thermal
cutout.
(C)
Remove
a
screw
holding
the
reinforcement
bracket
B
to
the
magnet-
ron
case.
(D)
Remove
air
guide
A
by
removing
1
screw
holding
it
to
the
magnetron
case.
(Fig.
11A
&
11B)
(E)
Remove
2
high
voltage
leads
from
filament
terminals.
(F)
Remove
4
screws
holding
the
magnetron.
NOTE:
To
prevent
microwave
leakage,
tighten
mounting
screws
proper-
ly
making
sure
there
is
no
gap
between
the
waveguide
and
the
magnetron.
CAUTION
When
connecting
2
filament
lead
wires
to
the
mag-
netron
terminals,
be
sure
to
connect
the
lead
wires
in
the
correct
position.
The
lead
wire
of
high
voltage
transformer
should
be
connected
to
“F
terminal”
and
the
lead
wire
with
500mA
fuse
from
high
voltage
capacitor
should
be
connected
to
“FA
terminal”.
(See
Fig.
11A
&
11B)
Removal
of
Positive
Lock
connector
The
positive
lock
connector
is
a
specially
designed
loose
free
connector
and
you
will
find
this
connector
in
many
lead
wire
connections.
To
re-
move
this
connector,
pull
the
lead
wire
by
pressing
an
extruded
lever
in
the
center
of
receptacle
terminal
as
shown
in
Fig.
11C.
2.
Replacement
of
the fan
motor
(A)
Disconnect
all
lead
wires
from
fan
motor,
noise
filter
and
high
voltage
capacitor.
(Refer
paragraph
“Removal
of
Positive
Lock
Connector”
and
Fig.
11C.)
(B)
Remove
6
screws
holding
the
back
panel.
(Fig.
12A)
(C)
Remove
3
screws
holding
the
fan
motor
bracket.
(Fig.
12B)
(D)
Pull
the
fan
motor
with
the
bracket
toward
you.
(E)
Remove
fan
blade
from
the
fan
motor
shaft
by
pulling
it
straight
out.
(F})
Remove
the
fan
motor
by
removing
2
screws
holding
it
to
the
fan
motor
bracket.
(Fig.
12C)
FAN MOTOR
NE-992/NE-993
NE-972
THERMAL CUTOUT
500 mA FUSE

3.
Replacement
of
the
digital
programmer
circuit
(D.P.C.)
NOTE:
Be
sure
to
ground
any
static
electric
charge
built
up
in
your
body,
LOW
VOLTAGE
before
handling
the
D.P.C..
TRANS
OnMER
(A)
Unplug
the
5-pin
connector
(CN3)
from
the
D.P.C..
J
(B)
Unplug
the
3-pin
connector
(CN4)
from
the
D.P.C..
(NE-992,
NE-993
only)
Caution
when
removing
connector
CN4
Sage
This
connector
is
a
special
type
which
may
be
very
hard
to
remove
just
by
pulling
directly
outward.
Instead
it
can
be
removed
easily
by
simply
grasping
it
by
the
ends
and
rocking
it
side
to
side
while
pulling.
(Fig.
14B)
(C)
Unplug
6-pin
(CN5),
6-pin
(CN1)
and
9-pin
(CN6)
connectors
from
the
D.P.C..
(D)
Disconnect
al!
lead
wires
from
the
power
relay
(2),
(3)
and
(5).
(E)
Remove
a
screw
holding
the
grounding
lead
wire
of
D.P.C..
(NE-972
only)
(F)
Remove
a
screw
holding
the
tab
of
membrane
key
board.
(G)
Remove
2
screws
to
release
escutcheon
base
assembly.
(Fig.
13A
&
13B)
Fig.
13A
NOTE:
The
escutcheon
base
assembly
is
also
mounted
to
oven
with
a
catch
hook,
located
at
upper
left
comer.
Release
the
catch
hook
NE-992/NE-993
by
using
flat
screwdriver
or
the
like
when
removing.
ESCUTCHEON
BASE
(H)
Release
CN2
connectors
lid
of
DPC
and
pull
off
the
flat
cable
of
the
membrane
key
board.
(Fig.
14A
&
14B)
(1)
Remove
2
screws
holding
the
DPC.
(Fig.
14A
&
14B)
(J)
Separate
the
DPC
from
escutcheon
base
by
carefully
freeing
the
2
catch
hooks
on
escutcheon
base
while
pulling
outward.
To
be
continued
for
replacement
of
the
membrane
key
board
(K)
Push
the
corner
part
of
membrane
key
board
(point
A
in
Fig.
15)
from
back
side
of
escutcheon
base
by
using
flat
screwdriver
or
the
like
and
peel
off
the
membrane
key
board
from
escutcheon
base.
(Fig.
15)
NOTE:
The
membrane
key
board
is
attached
to
the
escutcheon
base
with double faced adhesive tape.
Installation procedure of membrane key board
(A)
Insert
the
flat
cable
and
grounding
tab
of
membrane
key
board
to
holes
of
escutcheon
base.
:
(B)
Set
the
right
side
edge
of
key
board
to
the
right
side
bezel
of
escutcheon
base.
Fig.
13B
(C)
Insert
the
left
side
edge
of
key
board
to
the
left
side
bezel
of
escutch-
eon
base
while
expand
the
center
line
of
membrane
key
board.
NE-972
(D)
Press
down
the
membrane
key
board
by
soft
cloth.
40-PIN FLAT
CABLE (CN2)
enais PIN? {ITA GROUNDING
[ LEAD WIRE
CN1(4 PIN)
RY5
RY6
CN4(10 PIN}
RY2
Fig. 14A
NE-992/ NE-993
FLAT CABLE OF
MEMBRANE KEY BOARD
11-PIN FLAT
POINT
(A)
CABLE
(CN2),
ESCUTCHEON
BASE
PIN)
i=,
=*
:
FLAT
PIN?
SCREWDRIVER
TAB
OF
PIN)
MEMBRANE
KEY
BOARD
PIN)
Fig.
15
Fig.
14B