Sharp R-950A User manual

R-950A
SX734R950APM/
CONVECTION
MICROWAVE OVEN
MODEL R-950A
In interests of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
SERVICE MANUAL
SHARP CORPORATION
TABLE OF CONTENTS
Page
CAUTION, MICROWAVE RADIATION ............................................................................................................. 1
WARNING...........................................................................................................................................................1
PRODUCT SPECIFICATIONS.......................................................................................................................... 2
GENERAL INFORMATION ................................................................................................................................ 2
APPEARANCE VIEW........................................................................................................................................ 3
OPERATION SEQUENCE ................................................................................................................................ 4
FUNCTION OF IMPORTANT COMPONENTS ................................................................................................. 7
SERVICING ..................................................................................................................................................... 10
TEST PROCEDURE ........................................................................................................................................ 12
TOUCH CONTROL PANEL ASSEMBLY ......................................................................................................... 19
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE............................................................ 24
MICROWAVE MEASUREMENT ..................................................................................................................... 30
WIRING DIAGRAM ......................................................................................................................................... 31
PICTORIAL DIAGRAM.................................................................................................................................... 34
CONTROL PANEL CIRCUIT ........................................................................................................................... 35
PRINTED WIRING BOARD ............................................................................................................................. 36
PARTS LIST..................................................................................................................................................... 37
HELP
AUTO
COOK
AUTO
ROAST AUTO
GRILL AUTO
BAKE
OUTO
REHEAT
POWER
LEVEL
EASY
DEFROST KITCHEN
TIMER
STOP
CLEAR
CLOCK
SIMUL
GRILL
SIMUL
CONVEC GRILL
CONVEC
LESS MORE
PREHEAT
Info Display
12345
6789O
I
NSTANT COOK

START
40˚C 70˚C 130˚C 150˚C 160˚C
180˚C 200˚C 220˚C 230˚C 250˚C
1. Red Meat
2. Poultry
3. Pork
1. Cake
2. Fruit Pie
3. Cookies
1. Steak
2.
Chiken Pieces

3. Fish
Convection & Grill
%
HELP
AUTO INFO
COOKLbs Kg Oz Pcs

R-950A
41
6
45
123
6
45
123
A
B
C D E F
G H
A
B
C D E F
G H
OVEN AND CABINET PARTS
1-13
7-18 2-1
7-24
7-16
2-6
7-12
A
7-4
7-24
1-22
7-24
4-32
7-19
4-33
4-41
4-15
7-26
1-16
7-10
7-17
TO OVEN 
BASE PLATE
7-3
4-8
4-4
4-10 7-1
4-36
4-12
1-12
7-21
7-28 7-27
4-9
7-11
7-21x2
x2
x2
7-1
7-14
7-4
4-10 1-17
4-30
4-7 7-11
4-1
4-22
4-23
7-11 x 3
6-10
7-12
4-3
4-2
1-5
7-19
1-1
7-16
7-1
7-4
1-10
4-21 1-3
7-19
7-23 x2
7-6
1-21
7-18
2-4
2-3-2
2-3-1
7-22
x2
4-28
7-7
4-16
4-24
4-24
7-29
7-29
4-38
4-6 7-15
4-38
x 5
7-2
6-9
7-2
7-24
4-47
4-34
4-25
x3 4-29
6-4
1-25
2-3
x4 x4
1-11
7-22
7-19
x3 4-5
1-3
6-7
1-20 4-31
A
x3
7-1
2-5
7-13
7-5
x4
x9
4-11
4-26 4-27
4-18
4-20
7-9
7-16
4-19
1-9
1-14 7-17
4-17
4-14
4-39 7-16
7-2
4-49
2-2
1-18
2-9
x2
2-8
7-8x3
4-35
7-8 x3
1-19
7-17
x2
7-17
x2
x2
1-26
7-1
4-44
7-1
4-48
7-17
6-7
4-42
4-14
7-18 7-18
1-15
6-12
1-7
7-16
2-7
1-8
1-9
1-2
4-46
4-45
4-43
1-23
7-20
4-40
1-24
7-25
1-4
7-4
7-4
1-6
4-37
4-13

R-950A
42
'97SHARP CORP. (11S0.070E) Printed in Japan
6
45
123
6
45
123
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
MISCELLANEOUS
DOOR PARTS
CONTROL PANEL PARTS
5-3
5-11
5-1
5
Actual wire harness may be different than illustration.
6-4
6-1 6-5
6-6
6-2
5-10
5-10
5-9
5-5
5-4
5-7
5-8
5-6
5-2
5-5
7-18
7-18
3 - 5
3 - 4
x 2
3 - 7
3 - 3
3-1D 3-1E
3 - 2
3-2-1
3-2-3
3-2-2
3 - 6
3 - 6
3 - 6
3 - 1
6 - 8

R-950A
37
PARTS LIST
*
*
*
*
∆
ELECTRICAL PARTS
1- 1 FH-DZA058WRK0 High voltage rectifier assembly 1 AL
1- 2 FH-HZA041WRE0 Thermistor assembly 1 AN
1- 3 QACC-A084WRE0 Power supply cord 1 AD
1- 4 QFS-BA009WRE0 Fuse 20A 1 AH
1- 5 QFS-TA013WRE0 Temperature fuse 150˚C (Magnetron) 1 AG
1- 6 FPWBFA312WRK0 Noise filter 1 AY
1- 7 QSOCLA022WRE0 Oven lamp socket 1 AG
1- 8 QSW-MA111WRE0 Monitor switch 1 AK
1- 9 QSW-MA110WRE0 2nd. interlock relay control switch and Damper switch 2 AK
1-10 QSW-MA110WRE0 1st. and lower latch switch 1 AK
1-11 RC-QZA192WRE0 High voltage capacitor 1 AX
1-12 RHET-A140WRE0 Convection heater 1 AY
1-13 RLMPTA069WRE0 Oven lamp 1 AK
1-14 RMOTDA191WRE0 Damper motor 1 AS
1-15 RMOTDA223WRE0 Turntable motor 1 AZ
1-16 RMOTEA303WRE0 Cooling fan motor 1 AX
1-17 RMOTEA284WRE0 Convection motor 1 AZ
1-18 RR-WZA022WRE0 Monitor resistor 0.8Ω20W 1 AK
1-19 RTHM-A048WRE0 Thermal cut-out 170˚C (Conv.) 1 AH
1-20 RTHM-A074WRE0 Thermal cut-out 95˚C (Fan) 1 AH
1-21 RTRN-A543WRE0 Power transformer 1 BR
1-22 RV-MZA222WRE0 Magnetron 1 BN
1-23 RHET-A191WRE0 Grill heater 2 AX
1-24 QFSHDA019WRE0 Fuse holder 1 AH
1-25 QFS-CQ001YBE0 Fuse 10A 1 AE
1-26 RTHM-A106WRE0 Thermal cut-out 125˚C (Grill) 1
CABINET PARTS
2- 1 GCABUA463WRP0 Outer case cabinet 1 BF
2- 2 MLEVPA122WRF0 Switch lever 1 AD
2- 3 FDAI-A181WRY0 Base cabinet 1 AR
2-3-1 GCOVHA156WRP0 Turntable motor cover 1 AB
2-3-2 XHTSD40P08RV0 Screw; 4mm x 8mm 1 AA
2- 4 GLEGPA056WRE0 Foot 4 AD
2- 5 GCABDA088WRW0 Rear cabinet 1 AV
2- 6 LHLDKA009WRF0 Cord holder 1 AG
2- 7 LBNDKA036WRP0 Capacitor holder 1 AG
2- 8 FHNG-A092WRM0 Oven hinge (Lower) 1 AF
2- 9 PHOK-A043WRF0 Latch hook 1 AM
CONTROL PANEL PARTS
3- 1 CPWBFA757WRK0 Control unit 1 BU
3- 1A QCNCMA230DRE0 4-pin connector(A) 1 AC
3- 1B QCNCMA267DRE0 6-pin connector(E) 1 AC
3- 1C QCNCWA057DRE0 12-pin connector(G) 1 AF
3- 1D RV-KXA078DRE0 Fluorescent display tube 1 BD
3- 1E PCUSGA381WRP0 Cushion 2 AG
C1 RC-KZA087DRE0 Capacitor 0.1µF 50V 1 AB
C2 VCEAB31VW108M Capacitor 1000µF 35V 1 AF
C5 RC-KZA087DRE0 Capacitor 0.1µF 50V 1 AB
C6 VCEAB31VW106M Capacitor 10µF 35V 1 AA
C7-8 VCKYD11CY103N Capacitor 0.01µF 16V 2 AH
C9 VCTYF31HF103Z Capacitor 0.01µF 50V 1 AB
C10 RC-KZA087DRE0 Capacitor 0.1µF 50V 1 AB
C11 VCEAB31EW226M Capacitor 22µF 25V 1 AA
C20 VCEAB31VW106M Capacitor 10µF 35V 1 AA
C21 VCEAB31HW104M Capacitor 0.1µF 50V 1 AM
C22 RC-KZA087DRE0 Capacitor 0.1µF 50V 1 AB
C30 VCKYD11CY103N Capacitor 0.01µF 16V 1 AH
C50 VCKYD11CY103N Capacitor 0.01µF 16V 1 AH
C60 VCKYD11CY103N Capacitor 0.01µF 16V 1 AH
C70 RMPTEA009DRE0 Capacitor array 330pF x 4 1 AE
CF1 RCRS-A035DRE0 Ceramic resonator (CST4.19MGW) 1 AG
D1-4 VHD11ES1///-1 Diode (11ES1) 4 AB
D7 VHD1SS270A/-1 Diode (1SS270ATA) 1 AA
D20-26 VHD1SS270A/-1 Diode (1SS270ATA) 7 AA
D27 VHD1SS270A/-1 Diode (1SS270ATA) 1 AA
D30-31 VHD1SS270A/-1 Diode (1SS270ATA) 2 AA
D70-77 VHD1SS270A/-1 Diode (1SS270ATA) 8 AA
IC1 RH-IZA850DRE0 LSI 1 AW
Q3 VSKRA101M//-3 Transistor (KRA101M) 1 AB
Q4 VSDTA123ES/-3 Transistor (DTA123E) 1 AA
Note: The parts marked "∆" may cause undue microwave exposure.
The parts marked "*" are used in voltage more than 250V.
REF. NO. PART NO. DESCRIPTION Q'TY CODE
∆
∆

R-950A
38
Note: The parts marked "∆" may cause undue microwave exposure.
The parts marked "*" are used in voltage more than 250V.
REF. NO. PART NO. DESCRIPTION Q'TY CODE
∆
Q20-23 VSKRA101M//-3 Transistor (KRA101M) 4 AB
Q24-25 VSKRA223M//-3 Transistor (KRA223M) 2 AB
Q26 VSKRC243M//-3 Transistor (KRC243M) 1 AB
Q27 VSKRA223M//-3 Transistor (KRA223M) 1 AB
Q40 VSKRA101M//-3 Transistor (KRA101M) 1 AB
Q60 VSKRC101M//-3 Transistor (KRC101M) 1 AB
Q90-91 VSKRA101M//-3 Transistor (KRA101M) 2 AB
R3-4 VRS-B13AA471J Resistor 470 ohm 1W 2 AA
R7-8 VRD-B12EF472J Resistor 4.7k ohm 1/4W 2 AA
R10-11 VRS-B13AA180J Resistor 18 ohm 1W 2 AA
R30 VRD-B12EF153J Resistor 15k ohm 1/4W 1 AA
R31 VRD-B12EF472J Resistor 4.7k ohm 1/4W 1 AA
R40 VRD-B12EF332J Resistor 3.3k ohm 1/4W 1 AA
R50 VRD-B12EF153J Resistor 15k ohm 1/4W 1 AA
R51 VRD-B12EF472J Resistor 4.7k ohm 1/4W 1 AA
R62 VRN-B12EK753F Resistor 75k ohm(F) 1/4W 1 AA
R63 VRN-B12EK101F Resistor 100 ohm(F) 1/4W 1 AA
R64 VRN-B12EK222F Resistor 2.2k ohm(F) 1/4W 1 AA
R70-81 VRD-B12EF332J Resistor 3.3k ohm 1/4W 12 AA
R90-94 VRD-B12EF104J Resistor 100k ohm 1/4W 5 AA
RY1-3 RRLY-A083DRE0 Relay (OMIF-S-118LM) 3 AK
RY4-6 RRLY-A078DRE0 Relay (OJ-SS-118LM) 3 AG
RY7 RRLY-A083DRE0 Relay (OMIF-S-118LM) 1 AK
SP40 RALM-A014DRE0 Buzzer (PKM22EPT) 1 AG
T1 RTRNPA089DRE0 Transformer 1 AU
VRS1 RH-VZA032DRE0 Varistor (10G471K) 1 AE
ZD3 VHEHZ5C2///-1 Zener diode (HZ5C-2) 1 AA
ZD4 VHEHZ4A2///-1 Zener diode (HZ4A2) 1 AA
3- 2 DPNLCB460WRK0 Control panel frame with key unit 1 BE
3- 2-1 FUNTKA836WRE0 Key unit 1 BA
3- 2-2 JBTN-B060WRF0 Open button 1 AF
3- 2-3 MSPRCA050WRE0 Open button spring 1 AB
3- 3 LANGTA340WRW0 Control panel back plate 1 AK
3- 4 MLEVFA057WRW0 Open lever 1 AE
3- 5 NSFTTA042WRE0 Open shaft 1 AE
3- 6 XEPSD30P10XS0 Screw ; control unit mtg. 3 AA
3- 7 XCPSD40P12000 Screw ; control panel back plate mtg. 2 AA
OVEN PARTS
4- 1 FOVN-A402WRY0 Oven cavity assembly 1 BV
4- 2 FROLPA072WRK0 Turntable support 1 AL
4- 3 NTNT-A019WRH0 Turntable tray 1 AT
4- 4 FBRGMA002WRE0 Bearing ass’y 1 AQ
4- 5 PREFHA028WRW0 Thermal protection plate (left) 1 AR
4- 6 LANGTA196WRW0 Bearing mounting plate 1 AD
4- 7 LBNDK0054WRE0 Heater element holder 2 AB
4- 8 LFIX-A013WRW0 Bearing holder plate 1 AB
4- 9 NFANMA019WRW0 Convection fan 1 AE
4-10 NPLYBA025WRF0 Pulley (F) 2 AC
4-11 FDUC-A279WRK0 Heater duct assembly 1 AT
4-12 PFPF-A138WRE0 Thermal protection sheet (left) 1 AK
4-13 LANGQA410WRP0 Thermal cut-out mounting plate 1 AG
4-14 PCUSUA167WRP0 Cushion 2 AF
4-15 PCUSUA424WRP0 Cushion 1 AG
4-16 PDUC-A680WRW0 Steam duct assembly 1 AY
4-17 MCAMPA030WRF0 Damper cam 1 AC
4-18 NSFTTA114WRE0 Damper shaft 1 AB
4-19 FFTA-A034WRK0 Damper door ass’y 1 AM
4-20 PDUC-A269WRW0 Damper duct 1 AK
4-21 PCUSGA410WRP0 Cushion 1 AD
4-22 NCPL-A021WRF0 Turntable coupling 1 AE
4-23 PCOVPA301WRE0 Waveguide cover 1 AE
4-24 PCUSUA197WRP0 Cushion 2 AD
4-25 PGLSPA485WRE0 Light glass 1 AF
4-26 PFPF-A139WRE0 Thermal protection sheet (Right) 1 AF
4-27 PREFHA053WRW0 Thermal protection plate (Right) 1 AP
4-28 PSKR-A153WRW0 Air guide (Bottom) 1 AK
4-29 PSKR-A329WRW0 Divide plate (Right) 1 AM
4-30 LANGQA407WRW0 Convection motor mounting plate 1 AG
4-31 LANGQA369WRP0 Thermal cut-out mounting angle 1 AC
4-32 NFANJA020WRE0 Fan blade 1 AE
4-33 PDUC-A270WRF0 Cooling fan duct 1 AL
4-34 LANGFA089WRW0 Chassis support 1 AE
4-35 MHNG-A165WRM0 Oven hinge (Upper) 1 AE
4-36 NBLTKA005WRE0 Convection fan belt 1 AF
4-37 LANGQA475WRP0 Noise unit angle 1 AR
∆

R-950A
39
Note: The parts marked "∆" may cause undue microwave exposure.
The parts marked "*" are used in voltage more than 250V.
REF. NO. PART NO. DESCRIPTION Q'TY CODE
∆
∆
∆
∆
*
4-38 PCUSUA196WRP0 Cushion 2 AD
4-39 PCUSUA425WRP0 Damper duct cushion 1 AG
4-40 PCUSGA236WRP0 Cushion 1 AC
4-41 PSKR-A171WRW0 Magnetron air guide 1 AE
4-42 PFPF-A064WRE0 Thermal protection sheet 1 AF
4-43 LANGQA397WRP0 Heater mounting angle 1 AG
4-44 PREFHA052WRW0 Grill cover 1 AK
4-45 QTANNA017WRW0 Short terminal 1 AD
4-46 PSHEPA487WRE0 Heater film 1 AA
4-47 PDUC-A689WRP0 Exhaust duct 1 AW
4-48 PSKR-A328WRP0 Grill duct cover 1 AR
4-49 PCUSGA493WRP0 Cushion 1 AB
DOOR PARTS
5 CDORFA779WRK0 Door panel assembly complete 1 BU
5- 1 DDORFA820WRY0 Door panel 1 BD
5- 2 PGLSPA499WRE0 Door glass 1 AN
5- 3 GCOVHA155WRF0 Choke cover 1 AP
5- 4 GWAKPA526WRR0 Door frame 1 BD
5- 5 LANGKA845WRW0 Glass bracket 2 AF
5- 6 LANGKA851WRT0 Latch angle 1 AF
5- 7 LSTPPA169WRF0 Latch head 1 AH
5- 8 MSPRTA081WRE0 Latch head spring 1 AA
5- 9 XCPSD40P08000 Screw; 4mm x 8mm 2 AA
5-10 XEPSD30P08XS0 Screw; 3mm x 8mm 4 AA
5-11 XEBSD30P08000 Screw; 3mm x 8mm 11 AA
MISCELLANEOUS
6- 1 FAMI-A088WRM0 Low rack (Broiling trivet) 1 AW
6- 2 FAMI-A087WRM0 High rack (Baking rack) 1 AW
6- 3 TCADCA651WRR0 Cook book 1 BK
6- 4 FW-VZB635WRE0 Thermistor harness 1 AT
6- 5 FW-VZB623WRE0 Main wire harness 1 BD
6- 6 QW-QZA202WRE0 High voltage wire A 1 AK
6 -7 TCAUHA054WRR0 Cord caution 1 AE
6- 8 TSPCNC517WRR0 Name plate 1 AC
6- 9 TCAUHA214WRR0 K caution label 1 AF
6-10 TLABNA224WRR0 Menu label 1 AE
6-11 TINSEA721WRR0 Operation manual 1 AP
6-12 TLABSA061WRR0 M10A label 1 AC
SCREWS, NUTS AND WASHERS
7- 1 XOTWW40P10000 Screw; 4mm x 10mm 16 AA
7- 2 XOTSE40P12000 Screw; 4mm x 12mm 4 AA
7- 3 XCTWW40P08000 Screw; 4mm x 8mm 2 AA
7- 4 XHTSD40P08RV0 Screw; 4mm x 8mm 5 AA
7- 5 LX-CZ0052WRE0 Special screw 2 AA
7- 6 XWVSD60-07000 Washer; 6mm x 0.7 mm 1 AA
7- 7 LX-WZA004WRE0 Washer 1 AA
7- 8 LX-CZA020WRE0 Special screw 6 AA
7- 9 XBPSD30P14K00 Screw; 3mm x 14mm 1 AA
7-10 XBPSD40P25000 Screw; 4mm x 25mm 2 AA
7-11 XBTWW40P06000 Screw; 4mm x 6mm 7 AA
7-12 XCTSD40P08000 Screw; 4mm x 8mm 7 AA
7-13 LX-CZA060WRE0 Special screw 1 AA
7-14 XBPSD40P06KS0 Screw; 4mm x 6mm 2 AA
7-15 LX-WZA022WRE0 Washer 1 AB
7-16 XCPSD40P08000 Screw; 4mm x 8mm 5 AA
7-17 XCPSD30P06000 Screw; 3mm x 6mm 9 AA
7-18 XOTSD40P12RV0 Screw; 4mm x 12mm 11 AA
7-19 XFPSD40P08K00 Screw; 4mm x 8mm 4 AA
7-20 XBPWW30P05K00 Screw; 3mm x 5mm 2 AA
7-21 XCBWW30P06000 Screw; 3mm x 6mm 4 AA
7-22 XFPSD40P08000 Screw; 4mm x 8mm 5 AA
7-23 XFPSD60P14JS0 Screw; 6mm x 14mm 2 AB
7-24 XOTSD40P12000 Screw; 4mm x 12mm 8 AA
7-25 XFPSD30P10000 Screw; 3mm x 10mm 1 AC
7-26 XNESD40-32000 Nut; 4mm x 3.2mm 2 AA
7-27 XNEUW40-32000 Nut; 4mm x 3.2mm 1 AA
7-28 XWSUW40-10000 Washer; 4mm x 1 mm 1 AA
7-29 LX-CZA029WRE0 Special screw 2 AA

R-950A
40
1. MODEL NUMBER 3. PART NO.
2. REF. NO. 4. DESCRIPTION
HOW TO ORDER REPLACEMENT PARTS
To have your order filled prompty and correctly, please furnish the following information.
INFORMATION FOR PARTS CHANGE
The transistors will be changed as follows, and new parts will be used for products from December 1997.
Interchangeability
A. OLD ↔NEW B. OLD →NEW C. OLD ←NEW D. OLD NEW
REPLACEMENT PART NO. Interchange- EFFECTIVE
REF.NO. DESCRIPTION OLD No. Q'ty NEW No. Q'ty ability FROM CODE
Q3, Q40
Q20-Q23 Transistor VSKRA101M//-3 8 VSDTA143ES/-3 8 A DEC/ '97 AB
Q90-Q91
Q24-Q25 Transistor VSKRA223M//-3 3 VSDTB143ES/-3 3 A DEC/ '97 AC
Q27
Q26 Transistor VSKRC243M//-3 1 VSDTD143ES/-3 1 A DEC/ '97 AB
Q60 Transistor VSKRC101M//-3 1 VSDTC143ES/-3 1 A DEC/ '97 AC
PACKING AND ACCESSORIES
4-3 TURNTABLE TRAY
6-11 OPERATION 
MANUAL 
6-3 COOK BOOK
4-2 TURNTABLE SUPPORT
TRAY PACKING FOAM
SPADPA198WRE0
DOOR PROTECTION SHEET
SPADPA178WRE0
MICROWAVE OVEN
TOP PAD ASSEMBLY
FPADBA362WRK0
PLASTIC BAG
SSAKHA012WRE0
TRAY HOLDER
(SPADFA348WRE0)
BOTTOM PAD ASSEMBLY
FPADBA363WRK0
Not replaceable items.
PACKING CASE
SPAKCC966WRE0

R-950A
1
SERVICE MANUAL
CONVECTION
MICROWAVE OVEN
R-950A
GENERAL IMPORTANT INFORMATION
ThisManualhasbeenpreparedtoprovideSharpCorp.Service
engineers with Operation and Service Information.
It is recommended that service engineers carefully study the
entire text of this manual, so they will be qualified to render
satisfactory customer service.
CAUTION
MICROWAVE RADIATION
DONOTBECOMEEXPOSED TO RADIATION FROMTHE
MICROWAVE GENERATOR OR OTHER PARTS
CONDUCTING MICROWAVE ENERGY.
Service engineers should not be exposed to the microwave
energy which may radiate from the magnetron or other
microwave generating devices if it is improperly used or
connected. All input and output microwave connections,
waveguides, flanges and gaskets must be secured. Never
operate the device without a microwave energy absorbing
load attached. Never look into an open waveguide or an-
tenna while the device is energized.
WARNING
Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is not any other visible damage with the oven.
Servicing and repair work must be carried out only by trained
service engineers.
All the parts marked "*" on parts list are used at voltages more
than 250V.
Removal of the outer wrap gives access to potentials above
250V.
All the parts marked "∆" on parts list may cause undue micro-
wave exposure, by themselves, or when they are damaged,
loosened or removed.
SHARP CORPORATION
OSAKA, JAPAN
PRODUCT SPECIFICATIONS
APPEARANCE VIEW
OPERATING SEQUENCE
FUNCTION OF IMPORTANT
COMPONENTS
SERVICING AND
TROUBLESHOOTING CHART
TEST PROCEDURE
TOUCH CONTROL PANEL
ASSEMBLY
COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE
MICROWAVE MEASUREMENT
WIRING DIAGRAM
PARTS LIST

R-950A
2
PRODUCT SPECIFICATIONS
ITEM DESCRIPTION
Power Requirements 220 Volts
50 Hertz
Single phase, 3 wire earthed
Power Consumption 1600 W (Microwave) 3150 W (Microwave + Convection)
1600 W (Convection) 2600 W (Microwave + Grill )
1050 W (Grill, 2600 W initially)
Power Output 900 watts (IEC-705)
Operating frequency of 2450MHz
Convection heater 1500 W
Grill heater 1000 W
Case Dimensions Width 627mm
Height 378mm
Depth 492mm
Cooking Cavity Dimensions Width 410mm
Height 245mm
Depth 410mm
Control Complement Touch Control System
Clock ( 1:00 - 12:59)
Timer (0 - 99 min. 99 sec.)
Microwave Power for Variable Cooking
Repetition Rate;
HIGH.............................................. Full power throughout the cooking time
MED HIGH........................................................ approx. 70% of Full Power
MED................................................................... approx. 50% of Full Power
MED LOW (DEFROST) .....................................approx. 30% of Full Power
LOW .................................................................. approx. 10% of Full Power
CONVECTION COOKING FUNCTION Temperature for Variable Cooking
CONVECTION................................................... 40 to 250˚C Temp. control
SIMUL CONVECTION.......................230˚C with 30% of microwave power
GRILL COOKING FUNCTION
GRILL ...................................................................................... Grill cooking
SIMUL GRILL ..........................Grill cooking with 30% of microwave power
HELP pad
AUTO REHEAT pad AUTO COOK pad
AUTO ROAST pad AUTO GRILL pad
AUTO BAKE pad MORE. LESS pads
POWER LEVEL pad EASY DEFROST pad
KITCHEN TIMER pad
NUMBER and TEMPERATURE pads
STOP/CLEAR pad CLOCK pad
INSTANT COOK/START pad
Set Weight Approx. 29 kg
GENERAL INFORMATION
WARNING
THIS APPLIANCE MUST BE EARTHED
IMPORTANT
THE WIRES IN THIS MAINS LEAD ARE COLOURED IN ACCORDANCE WITH THE FOLLOWING CODE:
GREEN-AND-YELLOW : EARTH
BLUE : NEUTRAL
BROWN : LIVE

R-950A
3
APPEARANCEVIEW
1. Ventilation opening
2. Oven lamp
3. Door hinges
4. Door safety latches
5. See through door
6. Door seal and sealing
surfaces
7. Door open button
8. Touch control panel
9. Digital readout
10.Wave guide cover
11.Coupling
12.Menu label
13.Rating label
14. low rack
15.High rack
16.Power supply cord
17.Turntable
18.Roller stay
19.Grill heater TOUCH CONTROL PANEL

1
10
19
2
12
9
8
7
517
18
14 15
13
11 4
6
3
4
16
HELP
AUTO
COOK
AUTO
ROAST AUTO GRILL AUTO BAKE
AUTO
REHEAT
POWER
LEVEL
EASY
DEFROST KITCHEN TIMER
STOP
CLEAR
CLOCK
SIMUL
GRILL
SIMUL
CONVEC GRILL
CONVEC
LESS MORE
PREHEAT
Info Display
12345
6789O
I NSTANT COOK 
START
AUTO COOK PAD
Press to cook 5 popular menus.  
AUTO ROAST PAD
Press to select 3 popular Roast me-
nus.

MORE ( ), LESS ( ) PADS 
Press to increase/decrease the time
in one minute increments during
cooking or to alter the cooking result
for the Automatic operations.

CONVECTION COOKING FUNCTION PADS
Press to cook with one of 3 function. 
GRILL COOKING FUNCTION PADS
Press to cook with either function.
POWER LEVEL PAD
Press to select microwave power set-
ting. If not pressed, HIGH is automat-
ically selected.

NUMBER AND TEMPERATURE PADS
Press to enter cooking times, clock
time or convection temperature.
STOP/CLEAR PAD
Press to clear during programming.
Press once to stop operation of oven
during cooking; press twice to can-
cel cooking program.
HELP PAD
Press to select auto start, informa-
tion guide on/off, child lock, dem-
onstration modes or info on pad.
Press to get cooking information.

AUTO REHEAT PAD
Press to select 4 popular Reheat menu.

AUTO BAKE PAD
Press to select 3 popular Baked
menus.
AUTO GRILL PAD
Press to select 3 popularGrill me-
nus.


KITCHEN TIMER PAD
Press to set timer.


EASY DEFROST PAD
Press to defrost meat by entering
weight.

INSTANT COOK/START PAD
Press once to cook for 1 minute at
HIGH or increase by 1 minute multi-
ples each time this pad is pressed
during Microwave, Convection, Grill
or Simul cooking. Press to start oven
after setting programs.

CLOCK PAD
Press to set Clock
Indicator
40˚C 70˚C 130˚C 150˚C 160˚C
180˚C 200˚C 220˚C 230˚C 250˚C
HELP
AUTO
COOKKg Pcs
1. Red Meat
2. Poultry
3. Pork
1. Cake
2. Fruit Pie
3. Cookies
1. Steak
2.
Chiken Pieces 
3. Fish
Convection & Grill

R-950A
4
The following is a description of component functions
during oven operation.
Relay and Components Connection
RELAY CONNECTED COMPONENT
RY1 Oven lamp/ Turntable motor
RY2 Power transformer
RY3 Convection heater
RY4 Damper motor
RY5 Convection motor
RY6 Fan motor
RY7 Grill heater
OFF CONDITION
Closing the door activates all door interlock switches: 1st.
latchswitchand2nd.interlockrelaycontrolswitch.(Inthis
condition, the monitor switch contacts are closed.)
Whenoven is plugged in awall outlet (220V,50Hz), rated
voltage is supplied to the control unit. (Figure O-1):
1. The display flashes “SHARP”, "MICRO-", "WAVE",
'OVEN".
To set any programmes or set the clock, you must first
touch the STOP/CLEAR pad.
“ : “ appears in the display and the time counts up
every minute.
NOTE: When the oven door is opened, the oven lamp
comes on at this time.
2. A signal is input to the control unit, energizing the coil
ofshut-offrelay(RY4).RY4contactsclose,completing
a circuit to the damper motor. The damper motor now
operates moving the damper to the open position,
therebyclosingthe contacts of damperswitchinputsa
signal to the control unit. The coil of relay RY4 is de-
energized,openingitscontacts,therebyturningoffthe
damper motor.
MICROWAVE COOKING CONDITION
HIGH COOKING
Enter cooking time by pressing the NUMBER pads and
then select microwave cooking and power level by press-
ing the POWER LEVEL pad. When the START pad is
touched, the following operations occur:
1. The contacts of relays are closed and components
connected to relays are turned on (RY1, RY2, RY6).
(Figure O-2)
2. Rated voltage is supplied to the primary winding of the
power transformer. The voltage is converted to about
3.3 volts A.C. output on the filament winding and high
voltage of approximately 2260 volts A.C. on the high
voltage winding.
3. The filament winding voltage (3.3 volts) heats the
magnetronfilamentandthehighvoltage(2260volts)is
sent to the voltage doubling circuit.
4 The 2450 MHz microwave energy produced in the
magnetron generates a wave length of 12.24 cm. This
energyischannelledthroughthewaveguide(transport
channel)into the oven cavity,wherethe food isplaced
to be cooked.
5. Upon completion of the cooking time, the power
transformer, oven lamp, etc. are turned off and the
generation of microwave energy is stopped. The oven
will revert to the OFF condition..
6 When the door is opened during a cook cycle, the
monitor switch, 1st. latch switch and 2nd. interlock
relay control switch are activated with the following
results. The circuits to the turntable motor, cooling fan
motorandhighvoltagecomponentsarede-energized,
the oven lamp remains on and the digital read-out
displaysthetimestillremaininginthe cook cyclewhen
the door was opened.
7. The monitor switch is electrically monitoring the
operation of the 1st. latch switch and 2nd. interlock
relay control switch and is mechanically associated
with the door so that it will function in the following
sequence.
1) When the door opens from a closed potion, the 1st.
latch switch and the 2nd. interlock relay control switch
opentheircontacts,andthenthemonitorswitchcontacts
close.
2) When the door is closed, from the open position, the
monitorswitchcontactsfirstopen,andthenthecontacts
of the 1st. latch switch and 2nd. interlock relay control
switch must be closed.
If the common and normal open contacts of 1st. latch
switch and the 2nd. interlock relay fail with their contacts
closedwhenthedoorisopened,theclosingofthemonitor
switch contacts will form a short circuit through the fuse,
1st. latch switch and the 2nd. interlock relay, causing the
monitor fuse to blow.
MEDIUM HIGH, MEDIUM, MEDIUM LOW, LOW
COOKING
When variable cooking power is programmed, the rated
voltageissupplied to the powertransformerintermittently
through the contacts of the relay (RY2) which is operated
by the control unit within a 32-second time base. Micro-
wave power operation is follows:
VARI MODE ON TIME OFF TIME
HIGH (100% power) 32 sec. 0 sec.
MED HIGH (approx. 70% power) 24 sec. 8 sec.
MED (approx. 50% power) 18 sec. 14sec.
MED LOW (approx. 30% power) 12 sec. 20 sec.
LOW (approx. 10% power) 6 sec. 26 sec.
NOTE: TheON/OFFtimeratiodoesnotexactlycorrespond
to the percentage of microwave power, because
approx. 2 seconds are needed for heating up the
magnetron filament.
CONVECTION COOKING CONDITION
PREHEATING CONDITION (Figure O-3)
Press the PREHEAT pad and then select preheating
temperature by pressing the temperature pad. When the
START pad is touched, the following operations occur:
1. The coil of shut-off relays RY1+RY5+RY6 are
energized,the oven lamp,coolingfan motor, turntable
motor and convection motor are turned on.
2. The coil of relay (RY4) is energized by the CPU unit.
The damper is moved to the closed position, opening
OPERATION SEQUENCE

R-950A
5
thedamperswitchcontacts.Theopeningofthedamper
switch contacts sends a signal to the LSI on the CPU
unit de-energizing the relay (RY4) and opening the
circuit to the damper motor.
3. Thecoil of heaterrelay(RY3) is energizedby the CPU
unit and the main supply voltage is added to the
convection heater.
4. When the oven temperature reaches the selected
preheat temperature, the following operations occur:
4-1. The heater relay (RY3) is de-energized by the CPU
unit temperature circuit and thermistor, opening the
circuit to the convection heater.
4-2. The oven will continue to function for 30 minutes,
turning the convection heater on and off, as needed
to maintain the selected preheat temperature. The
oven will shutdown completely after 30 minutes.
CONVECTION COOKING CONDITION (Figure O-3)
When the preheat temperature is reached, a beep signal
will sound indicating that the holding temperature has
beenreachedintheovencavity. Open thedoorandplace
the food to be cooked in the oven. Press the CONVEC-
TION pad and then enter the cooking temperature by
pressingthetemperaturepad.Andthenenterthecooking
time by pressing the NUMBER pads. When the START
pad is touched, the following operations occur:
1. The numbers of the digital read-out start the count
down to zero.
2. Theovenlamp,turntablemotor,coolingfanmotorand
convection motor are energized.
3. Heaterrelay(RY3)isenergized(ifthecavitytemperature
is lower than the selected temperature) and the main
supply voltage is applied to the convection heater to
return to the selected cooking temperature.
4. Upon completion of the cooking time, the audible
signal will sound, and oven lamp, turntable motor,
cooling fan motor, convection motor and convection
heater are de-energized. At the end of the convection
cycle, if the cavity air temperature is above 118˚C, the
circuit to (RY6) will be maintained (by the thermistor
circuit) to continue operation of the cooling fan motor
untilthetemperaturedropsbelow118˚C,atwhichtime
therelaywillbede-energized,turningoffthefanmotor.
Relay (RY5) will however, open as soon as the
convectioncyclehasended,turning offtheconvection
fanmotor.Thiswillnowcoolandallowthedamperdoor
to open.
5. At the end of the convection cook cycle, shut-off relay
(RY4) is energized turning on the damper motor. The
damper is returned to the open position, closing the
damper switch contacts which send a signal to the
control unit, de-energizing shut-off relay (RY4).
SIMUL CONVECTION COOKING CONDITION
(Figure O-5)
Press the SIMUL CONVEC pad. And then enter cooking
time by pressing the NUMBER pads. When the START
pad is touched, the following operations occur:
1. The numbers of the digital read-out start the count
down to zero.
2. The shut-off relays (RY1+RY5+RY6) are energized,
turning on the oven lamp, turntable motor, cooling fan
motor and convection motor.
3. The shut-off relay (RY4) is energized.
The damper door is closed from the open position.
4. The power supply voltage is added to the convection
heater and power transformer at the same time.
5. The convection heater operates through the heater
relay (RY3) contacts and the power transformer
operates through the cook relay (RY2) contacts.
6. Upon completion of the cooking time, the audible
signal will sound, and oven lamp, turntable motor,
cooling fan motor, convection motor and power
transformerarede-energized.Attheendofthecooking
cycle, if the cavity air temperature is above 118˚C, the
circuit to (RY6) will be maintained (by the thermistor
circuit) to continue operation of the cooling fan motor
untilthetemperaturedropsbelow118˚C,at whichtime
therelaywillbede-energized,turningoffthefanmotor.
The relationship between the convection and microwave
power operations are as follows.
16 SEC. 32 SEC.
SIMUL CONVECTION
MICROWAVE POWER
= APPROX. 30%
CONVECTION 
TEMPERATURE
= 230˚C
ON
OFF
ON
(MICRO.)
(CONVEC.)
NOTE:
1) The simul convection is programmed for 230˚C
with30%microwavepower.Themicrowavepower
and convection temperature can be changed, but
the High (100%) and 250˚C can not be selected.
2) The relay (RY2) is operated by the CPU unit to
supply within a 48 second time base microwave
energy.
3) Duringsimulconvectionoperation,theconvection
heater is energized only if the cavity temperature
drops below the set temperature.
4) The ON and OFF time ratio does not correspond
withthepercentageofmicrowavepower,because
approx. 2 seconds are needed for heating of the
magnetron filament.
5) "SIMUL" means "Simultaneous".
GRILL COOKING CONDITION (Figure O-4)
Press the GRILL pad and then enter the cooking time by
pressing the number pads. When the START pad is
touched, the following operations occur:
1. The coil of shut-off relays RY1+RY6+RY7 are
energized, the oven lamp, cooling fan motor and
turntable motor are turned on.
2. The coil of relay (RY4) is energized by the CPU unit.
The damper is moved to the closed position, opening
thedamperswitchcontacts.Theopeningofthedamper
switch contacts sends a signal to the LSI on the CPU
unit de-energizing the relay (RY4) and opening the
circuit to the damper motor.
3. Thecoilofrelay(RY7)isenergizedbytheCPUunitand
the main supply voltage is added to the grill heater.
4. At the initial period, the relays RY3 and RY5 are
energized and the convection heater and convection
motor are energized until the cavity air temperature
reaches 220˚C.
5. Whenthetemperatureexceeds220˚C, theconvection

R-950A
6
heater and convection motor are turn off.
6. Upon completion of the cooking time, the audible
signal will sound, and oven lamp, turntable motor,
cooling fan motor and grill heater are de-energized. At
the end of the grill cycle, the circuit to RY6 will be
maintained to continue operation of the cooling fan
motor for 3 minutes if the grill cooking time is longer
than 2 minutes, and if the cavity air temperature is
above118˚C,thecircuitto(RY6)willbemaintained(by
the thermistor circuit) to continue operation of the
cooling fan motor until the temperature drops below
118˚C, at which time the relay will be de-energized,
turning off the fan motor.
7. Attheendofthegrillcookcycle,shut-off relay (RY4) is
energizedturningonthedampermotor.Thedamperis
returned to the open position, closing the damper
switch contacts which send a signal to the control unit,
de-energizing shut-off relay (RY4).
SIMULGRILLCOOKING CONDITION (FigureO-6)
PresstheSIMULGRILLpad.Andthenentercookingtime
by pressing the NUMBER pads. When the START pad is
touched, the following operations occur:
1. The numbers of the digital read-out start the count
down to zero.
2. The shut-off relays (RY1+ RY6) are energized, turning
ontheovenlamp,turntablemotorandcoolingfanmotor.
3. The shut-off relay (RY4) is energized.
The damper door is closed from the open position.
4. The power supply voltage is added to the grill heater
and power transformer at the same time.
5. The grill heater operates through the relay (RY7)
contacts and the power transformer operates through
the cook relay (RY2) contacts.
6. Upon completion of the cooking time, the audible
signal will sound, and oven lamp, turntable motor,
cooling fan motor, grill heater and power transformer
arede-energized.Attheendofthesimulgrillcycle,the
circuit to RY6 will be maintained to continue operation
ofthecoolingfanmotorfor3minutesifthegrillcooking
time is longer than 2 minutes, and if the cavity air
temperatureisabove118˚C,thecircuitto(RY6)willbe
maintained (by the thermistor circuit) to continue
operationofthecoolingfanmotoruntilthetemperature
drops below 118˚C, at which time the relay will be de-
energized, turning off the fan motor.
The relationship between the convection and microwave
power operations are as follows.
16 SEC. 32 SEC.
SIMUL GRILL
MICROWAVE POWER
= APPROX. 30%
ON
OFF
ON
(MICRO.)
(GRILL)
NOTE:
1) TheSimulGrillisprogrammedwith30%microwave
power. The microwave power can be changed.
2) Therelay(RY2)isoperatedbytheCPUunittosupply
within a 48 second time base microwave energy.
3) During Simul Grill operation, the grill heater is
energized continuously. But after the Simul Grill
cooking exceeds 20 minutes, the RY2 will be de-
energized automatically turning off the power
transformer to protect the oven.
4) The ON and OFF time ratio does not correspond
withthepercentageofmicrowavepower,because
approx. 2 seconds are needed for heating of the
magnetron filament.
5) "SIMUL" means "Simultaneous".
AUTO COOK/AUTO REHEAT
AUTOCOOK/AUTOREHEATwillautomaticallycompute
andsetthemicrowavepowerandcookingtime.Selectthe
menubytouchingtheAUTOCOOK/AUTOREHEATpad.
Enter the weight / quantity by touching the Number pads.
When the START pad is touched, the oven works on
Microwave cooking mode according to the special cook-
ing sequence.
EASY DEFROST COOKING
The EASY DEFROST key is a special function key to
defrost meats and poultry faster and better. EASY DE-
FROST key has 4 defrost stages. EASY DEFROST auto-
maticallydefrostsroastbeef,etc.WhenEASYDEFROST
is selected and the food weight is entered by using the
number pads, the oven will cook according to the special
cooking sequence. (Figure O-2)
FIRE SENSING FEATURE (MICROWAVE MODE)
This model incorporates a sensing feature which will stop
the oven's operation if there is a fire in the oven cavity
during microwave cooking. This accomplished by the LSI
repeatedly measures the voltage across the temperature
measurement circuit (thermistor) during it's 32-seconds
timebasecomparingtheobtainedvoltagemeasurements.
Ifthemostrecent voltagemeasuredis300mVgraterthan
the previous voltage measured, the LSI judges it as a fire
inthe ovencavity and switchesoff the relays to thepower
transformer,fanmotorandconvectionmotor.TheLSIalso
stops counting down and closes the damper door so that
no fresh air will enter the oven cavity. Please refer to the
following section for a more detailed description.
Operation
Please refer to the timing diagrams below.
1. Thethermistoroperateswithina32-secondstimebase
and it is energized for three (3) seconds and off for 29
seconds. Two (2) seconds after the thermistor is
energized, the voltage across the temperature
measurementcircuit is sampledby the LSIand twenty
one (21) seconds after the thermistor is cut off the LSI
turns on the cooling fan for six (6) seconds.
2. The above procedure is repeated. If the difference
between the first voltage measured (in step 1) and the
voltage measured when the procedure is repeated
(step 2) is greater than 300mV the LSI makes the
judgment that there is a fire in the oven cavity and will
switch off the relays to the power transformer, fan
motor and convection motor. The LSI also stops
counting down and closes the damper door so that no
fresh air will enter the oven cavity.
3. Oncethefiresensorfeaturehasshuttheunitdown,the
programmed cooking cycle may be resumed by
pressing the "START" pad or the unit may be reset by
pressing the "CLEAR" pad.

R-950A
7
AUTO ROAST/ AUTO GRILL/ AUTO BAKE
AUTOROAST/AUTOGRILL/AUTOBAKEwillautomati-
cally compute and set the cooking mode, oven tempera-
ture, microwave power and the cooking time. Select the
menu by touching the AUTO ROAST, AUTO GRILL, or
AUTO BAKE pad, and enter the weight/ quantity by
touching the number pads. When the START pad is
touched, the oven works on Simul Cooking mode, Con-
vectionCookingmodeorGrillCookingmodeaccordingto
the special cooking sequence.
CONVECTION
MOTOR
THERMISTOR
Sensing 
Voltage
ON
OFF
ON
OFF
ON
OFF
0 2 24 30 64 (sec.)
3 sec.
Sensing the voltage across the temperature measurement circuit.
6 sec.
332 (sec.)
DOOR OPEN MECHANISM
The door is opened by pushing the open button on the
control panel, refer to the Figure D-1.
Whentheopenbuttonispushed,theopenleverpushesup
the switch lever, and then the switch lever pushes up the
the latch head. The latch heads are moved upward and
released from latch hook. Now the door will open.
LATCH HOOK
LATCH 
HEADS
2ND. INTERLOCK
RELAY CONTROL 
SWITCH
MONITOR SWITCH
1ST. LATCH SWITCH
SWITCH LEVER
OPEN LEVER
DOOR OPEN 
BUTTON
Figure D-1. Door Open Mechanism
1ST. LATCH SWITCH, 2ND. INTERLOCK RELAY
CONTROL SWITCH
1. Whentheovendoorisclosed,thecontacts(COM-NO)
must be closed.
2. When the oven door is opened, the contacts (COM-
NO) must be opened.
MONITOR SWITCH
1. Whenthedoorisclosed,thecontacts(COM-NC)must
be opened.
2. When the oven door is opened, the contacts (COM-
NC) must be closed.
3 Iftheovendoorisopenedandthecontacts(COM-NC)
of1st.latchswitchand2nd.interlockrelayfailtoopen,
the fuse M8A blows simultaneously with closing the
contacts (COM-NC) of the monitor switch.
CAUTION: BEFOREREPLACINGABLOWNFUSE M8A
TEST THE 1ST. LATCH SWITCH, 2ND. IN-
TERLOCKRELAY,MONITORSWITCHAND
MONITOR RESISTOR FOR PROPER OP-
ERATION. (REFER TO CHAPTER “TEST
PROCEDURE”).
THERMAL CUT-OUT 170˚C (CONV.)
The thermal cut-out protect the convection motor or outer
casecabinetagainstoverheating.Ifitstemperatureof the
termal cut-out goes up higher than 170˚C because the
convectionfanorcoolingfanis interrupted, theventilation
openingsareobstructedorotherabnormalmatteroccurs,
thermalcut-outwillopenandswitchofftheoven.Whenthe
oven cools itself down to the operating temperature of
155˚C,thecontactsofthethermalcut-outwillcloseagain.
THERMAL CUT-OUT 125˚C (GRILL)
Thisthermalcut-outprotectstheoutercasecabinetagainst
overheating.Ifthetemperaturegoesuphigherthan125˚C
because the fan motor is interrupted or the ventilation
openings are blocked, the thermal cut-out will open and
linevoltagestotheallelectricalpartswillbecutoffandthe
operation of the oven will be stopped. The defective
thermal cut-out must be replaced with a new one.
THERMAL CUT-OUT 95˚C (FAN MOTOR)
The thermal cut-out protect the fan motor against over-
heating. If its temperature goes up higher than 95˚C
because the fan motor is locked or the ventilation operat-
ing are blocked, the contacts of the thermal cut-out will
open and switch off all electrical parts. When the thermal
cut-out cools itself down to 75˚C, the contacts of the
thermal cut-out will close again.
TEMPERATURE FUSE 150˚C (MG)
This fuse protects the magnetron against overheating. If
the temperature goes up higher than 150˚C because the
FUNCTION OF IMPORTANT COMPONENTS

R-950A
8
TURNTABLE MOTOR
The turntable motor drives the turntable supporting plate
to rotate the turntable.
CONVECTION MOTOR
The convection motor drives the convection fan and
provides the heated air.
FAN MOTOR
Thefanmotordrivesabladewhichdrawsexternalcoolair.
This cool air is directed through the air vanes surrounding
the magnetron and cools the magnetron. This air is chan-
nelled through the oven cavity to remove steam and va-
poursgivenofffromtheheatingfoods.Itisthenexhausted
through the exhausting air vents at the oven cavity.
CONVECTION HEATER
Theconvectionheaterislocatedattheleftsideoftheoven
cavity. It is intended to heat air driven by the convection
fan.Theheatedairiskeptintheovenandforce-circulated
and reheated by the convection heater.
GRILL HEATER
Thegrillheaterisprovidedtobrownthefoodandislocated
on the top of the oven cavity.
CONVECTION COOKING SYSTEM
Thisovenisdesignedwithahotairheatingsystemwhere
foodis not directlyheated by theconvection heater, butis
heatedby forced circulationof the hotair produced bythe
convection heater. The air heated by the convection
heater is circulated through the convection passage pro-
vided on the outer casing of the oven cavity by means of
the convection fan which is driven by the convection
motor.Itthenenterstheinsideoftheoventhroughthevent
holesprovidedontheleftsideoftheoven.Next,thehotair
heatsthefoodontheturntableandleavestheovencavity
through the vent in the oven cavity left side wall. Without
leavingtheoven,thishotairisreheatedbytheconvection
heater, passes through the convection passage and en-
ters the inside of the oven cavity again, in a continuing
cycle. In this way, the hot air circulates inside the oven
cavity to raise its temperature and, at the same time,
comes into contact with the food being cooked. When the
temperature inside the oven cavity reaches the selected
temperature,theconvectionheaterisde-energized.When
the temperature inside the oven cavity drops below the
selected temperature, the convection heater is energized
again. In this way, the inside of the oven cavity is main-
tained at approximately the selected temperature.
When the convection time reaches 0, the convection
heater is de-energized and the convection fan stops
operating and the oven shuts off. Upon completion of the
cookingtime,theaudiblesignalwillsound,andovenlamp,
turntable motor, cooling fan motor and convection motor
arede-energized.Attheendoftheconvectioncycle,ifthe
cavity air temperature is above 118˚C, the circuit to RY6
will be maintained (by the thermistor circuit) to continue
operation of the cooling fan motor until the temperature
drops below 118˚C, at which time the relay will be de-
energized, turning off the fan motor. Relay RY5 will how-
ever, open as soon as the convection cycle has ended,
turningofftheconvectionfanmotor.Thiswillnowcooland
allow the damper door to open.
fan motor is interrupted, the air inlet duct is blocked or the
ventilation openings are obstructed, the fuse blows and
cuts off the power supplying to all electrical parts. The
defective fuse must be replaced with new rated one.
FUSE M10A 250V
1. If the wire harness or electrical components are short-
circuited,thisfuseblowstopreventanelectricshockor
fire hazard.
2. The fuse also blows when1st. latch switch and 2nd.
interlock relay remain closed with the oven door open
and when the monitor switch closes.
3. The fuse M10A also blows when asymmetric rectifier,
H.V. rectifier, H.V. wire harness, H.V. capacitor,
magnetronorsecondarywindingofpowertransformer
is shorted.
FUSE 20A
If the wire harness or electrical components are short-
circuited,thisfuseblowstopreventanelectricshockorfire
hazard.
ASYMMETRIC RECTIFIER
The asymmetric rectifier is a solid state device that pre-
vents current flow ins both directions. And it prevents the
temperature rise of the power transformer by blowing the
fuse M10A when the high voltage rectifier is shorted.
D2 D1
ASYMMETRIC
RECTIFIER HIGH VOLTAGE 
RECTIFIER
The rated peak reverse voltage of D1 of the asymmetric
rectifieris6KVTheratedpeakreversevoltageofD2ofthe
asymmetricrectifieris1.7KV.D1andD2oftheasymmet-
ric rectifier or high voltage rectifier are shorted when the
each peak reverse voltage goes beyond the each rated
peak reverse voltage. (The process of blowing the fuse
M10A.) .
1. The high voltage rectifier is shorted by any causes
when microwave cooking.
2. The peak reverse voltage of D2 of the rectifier goes
beyond the rated peak reverse voltage 1.7 KV in the
voltagedoubler circuit.
3. D2 of the rectifier is shorted.
4. Thelargeelectriccurrentsflowthroughthehighvoltage
winding of the power transformer.
5. The large electric currents beyond 10A flow through
the primary winding of the power transformer.
6. The fuse M10A blows by the large electric currents.
7. The power supply to the power transformer is cut off.
THERMISTOR
The thermistor is a negative temperature coefficient type.
Thetemperatureintheovencavityisdetectedthroughthe
resistance of the thermistor, and then the control unit
causes the heating element relay to operate, thus the
current to the heating element is turned ON/OFF.
MONITOR RESISTOR
The monitor resistor prevents the fuse M10A 250V burst-
ing when the fuse M10A 250V blows due to the operation
of the monitor switch.

R-950A
9
DAMPER OPEN-CLOSE MECHANISM
Usually, the damper is in the open position except during
convection cooking.
Damper position is set automatically by damper motor,
damper switch, motor cam and damper shaft.
Thesecomponents are operatedby a signalthat judges if
microwave cooking or convection cooking operation is
selected by the CPU unit.
Microwave Cooking:
Damper is in the open position, because a portion of
cooling air is channelled through the cavity to remove
steam and vapours given off from the heating foods.
It is then exhausted at the top of the oven cavity into a
condensation compartment.
Convection Cooking:
Damper is in the closed position, so that no hot air will be
allowed to leak out the oven cavity.
Damper Operation
1. When power supply cord is plugged in:
1-1. When power supply cord is plugged in, a signal is
sensedinthecontrolunit,andoperatesshut-offrelay
(RY4).
1-2. Contacts of shut-off relay (RY4) close, the damper
motor is energized, opening the damper door.
1-3. When the damper is moved to the open position by
the damper cam, damper switch is closed (ON
position).
1-4. The signal of damper switch is re-sensed in the
control unit and shut-off relay (RY4) is turned off.
1-5. Theratedvoltagetothedampermotorisstoppedand
the motor turns off.
2. When oven is microwave cooking:
Damper is in the open position
3. When oven is convection cooking:
3-1 Dampermotorisenergizedbytouchingtheconvection,
temperature and START pads.
3-2. When damper is in the closed position (damper
switchisOFF),itssignalissensedbythecontrolunit,
and shut-off relay (RY4) is de-energized.
3-3. The damper is held in the closed position during the
convection cooking operation.
3-4. At the end of the convection cooking, shut-off relay
(RY4)isenergized,andthedamper is returnedtothe
open position.
NOTE: If the damper door is not in the proper position,
closed during convection or open during
microwave,thecontrolunitwillstopovenoperation
after 1 minute.
Cooking Mode Operation of Damper
Microwave cooking OPEN
Convection cooking CLOSE
Grill cooking CLOSE
Simul Convection cooking CLOSE
Simul Grill cooking CLOSE
DAMPER DUCT
DAMPER
DAMPER CAM
DAMPER MOTOR
DAMPER SWITCH
DAMPER SHAFT
Figure D-2. Damper Mechanism
NOISE FILTER
The noise filter prevents the radio frequency interference
that might flow back in the power circuit.

R-950A
10
SERVICING
WARNING TO SERVICE PERSONNEL
Microwaveovenscontaincircuitrycapableofproducingveryhighvoltageandcurrent,contactwithanypartofthe
highvoltagecircuitwillresultinelectrocution.Highvoltagecapacitor,Powertransformer,Magnetron,Highvoltage
rectifier assembly, High voltage harness.
REMEMBER TO CHECK 4R
1) Reconnect all leads removed from components
during testing.
2) Replace the outer case (cabinet).
3) Reconnect the supply.
4) Run the oven. Check all functions.
Microwave ovens should not be run empty. To test for
the presence of microwave energy within a cavity,
place a cup of cold water on the oven turntable, close
the door and set the microwave timer for two (2)
minutes. Set the power level to HIGH and push the
START button. When the two minutes has elapsed
(timeratzero)carefullycheckthatthewaterisnowhot.
If the water remains cold carry out 3D checks and re-
examine the connections to the component being
tested.
IMPORTANT: If the oven becomes inoperative because
of a blown fuse M10A in the 1st. latch
switch-2nd.interlockrelay-monitorswitch
- monitor resistor circuit, check the 1st.
latch switch, 2nd. interlock relay, 2nd.
interlock relay control switch, monitor
switchand monitorresistorbeforereplac-
ing the fuse M10A.
REMEMBER TO CHECK 3D
1) Disconnect the supply.
2) Door opened, and wedged open.
3) Discharge high voltage capacitor.
WARNING: AGAINST THE CHARGE OF THE
HIGH-VOLTAGE CAPACITOR
Thehigh-voltagecapacitorremainschargedabout
60 seconds after the oven has been switched off.
Wait for 60 seconds and then short-circuit the
connectionofthehigh-voltagecapacitor(thatis,of
the connecting lead of the high-voltage rectifier)
against the chassis with the use of an insulated
screwdriver.
Sharprecommendthatwhereverpossiblefault-finding
is carried out with the supply disconnected. It may in,
some cases, be necessary to connect the supply after
the outer case has been removed, in this event carry
out 3D checks and then disconnect the leads to the
primary of the power transformer. Ensure that these
leads remain isolated from other components and the
ovenchassis.(Useinsulationtapeifnecessary.)When
the testing is completed carry out 3D checks and
reconnect the leads to the primary of the power trans-
former.
When all service work is completed and the oven is fully assembled, the microwave power output should be
checked and microwave leakage test should be carried out.
When troubleshooting the microwave oven, it is helpful to
follow the Sequence of Operation in performing the
checks.Manyofthepossiblecausesoftroublewillrequire
that a specific test be performed. These tests are given a
procedureletterwhichwillbefoundinthe"TestProcedure
"section.
TROUBLESHOOTING GUIDE

R-950A
11
CK = Check / RE = Replace
RE SHORTED POWER CORD
CK LOW POWER SUPPLY VOLTAGE
CK WALL OUTLET
CK OPENED OR SHORTED WIRE HARNESS
RE OVEN LAMP OR SOCKET
 Q FOIL PATERN ON P.W.B.
 P RELAY (RY-7)
 P RELAY (RY-6)
 P RELAY (RY-5)
 P RELAY (RY-4)
 P RELAY (RY-3)
 P RELAY (RY-2)
 P RELAY (RY-1)
 O KEY UNIT
 N TOUCH CONTROL PANEL
 M NOISE FILTER
 L MONITOR RESISTOR
 K DAMPER MOTOR
 K CONVECTION MOTOR
 K TURNTABLE MOTOR
 K FAN MOTOR
 J THERMISTOR 
 I GRILL HEATER
 I CONVECTION HEATER
 H THERMAL CUT-OUT 
 H TEMPERATURE FUSE 150˚C 
 G MAIN FUSE 20A
 F MONITOR FUSE M10A
 E DAMPER SWITCH
 E MONITOR SWITCH
E 2ND. INTERLOCK RELAY CONTROL SWITCH
 E 1ST. LATCH SWITCH
 D HIGH VOLTAGE CAPACITOR
 C H.V. RECTIFIER ASSEMBLY
 B POWER TRANSFORMER
 A MAGNETRON
POSSIBLE CASE AND  DEFECTIVE PARTS
PROBLEM
CONDITION
OFF

CONDITION
COOKING

CONDITION

COMMON 
MODE
MICROWAVE

COOKING
CONDITION

CONVECTION

COOKING
CONDITION

GRILL
COOKING
CONDITION

Home fuse blows when power supply cord is plugged into wall outlet. Fuse M10A blows when power cord is plugged into wall outlet. Display does not show anything when power cord is first plugged into wall outlet. Display does not operate properly when STOP/CLEAR pad is touched. (" : " or the time of day should appear on the display with beep sound during normal condition.) Oven lamp does not light with door opened. Oven lamp does not light at all. Oven lamp light, but turntable motor does not operate. Cooling fan motor does not operate. The oven stops after 1 minute. Oven does not go into a cook cycle, when START pad is touched. Low or no power is produced during microwave cooking (The food is heated incompletely or not heated at all) Extremely uneven heating is produced in oven load (food). Function of variable cooking does not operate properly except HIGH power. CONV indicator lights, but convection heater does not heat. Temperature in the oven cavity is lower or higher than preset. Convection cycle runs 3 minutes then the oven shuts down. Grill heater does not heat. Initial back up by convection does not work properly. SIMUL CONVECTION COOKING CONDITION  SIMUL GRILL COOKING CONDITION See above "Microwave Cooking Condition" and "Convection Cooking Condition".
See above "Microwave Cooking Condition" and "Grill Cooking Condition".

R-950A
12
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
AMAGNETRON TEST
NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL
WHILE THE OVEN IS IN OPERATION.
CARRY OUT 3D CHECK.
Isolatethe magnetron fromhigh voltage circuitby removing allleads connected tofilament terminal.
Totestforanopencircuitfilamentuseanohmmetertomakeacontinuitytestbetweenthemagnetron
filament terminals, the meter should show a reading of less than 1 ohm.
Totestforshortfilamenttoanodecondition,connectohmmeterbetweenoneofthefilamentterminals
and the case of the magnetron (ground). This test should be indicated an infinite resistance. If a low
or zero resistance reading is obtained then the magnetron should be replaced.
MICROWAVE OUTPUT POWER (IEC 705)
The following test procedure should be carried out with the microwave oven in a fully assembled
condition (outer case fitted). Microwave output power from the magnetron can be measured by way
of IEC 705, i.e. it can be measured by using water load how much it can be absorbed by the water
load.Tomeasurethemicrowaveoutputpowerinthemicrowaveoven,therelationofcalorieandwatt
is used. When P(W) heating works for t(second), approximately P x t/4.187 calorie is generated. On
theotherhand,ifthetemperatureofthewaterwithV(ml)rises∆T(°C)duringthismicrowaveheating
period, the calorie of the water is V x ∆T.
The formula is as follows;
P x t / 4.187 = V x ∆T P (W) = 4.187 x V x ∆T / t
Our condition for water load is as follows:
Room temperature..............around 20°C Power supply Voltage.........Rated voltage
Water load.........1000 g Initial temperature...........10±2°C Heating time.........47 sec.
P = 90 x ∆T
Measuring condition:
1. Container
The water container must be a cylindrical borosilicate glass vessel having a maximum material
thickness of 3 mm and an outside diameter of approximately 190 mm.
2. Temperature of the oven and vessel
The oven and the empty vessel are at ambient temperature prior to the start the test.
3. Temperature of the water
The initial temperature of the water is (10±2)°C.
4. Select the initial and final water temperature so that the maximum difference between the final
water temperature and the ambient temperature is 5°C.
5. Selectstirringdevicesandmeasuringinstrumentsinordertominimizeadditionorremovalofheat.
6. The graduation of the thermometer must be scaled by 0.1°C at minimum and accurate
thermometer.
7. The water load must be (1000±5) g.
8. “t”ismeasuredwhilethemicrowavegeneratorisoperatingatfullpower.Magnetronfilamentheat-
up time is not included.
NOTE: The operationtime ofthemicrowave oven is“t +2”sec. 2sec.ismagnetron filamentheat-uptime.
Measuring method:
1. Measure the initial temperature of the water before the water is added to the vessel.
(Example: The initial temperature T1 = 11°C)
2. Add the 1 litre water to the vessel.
3. Place the load on the centre of the shelf.
4. Operate the microwave oven at HIGH for the temperature of the water rises by a value ∆T of
(10 ±2)°C.
5. Stir the water to equalize temperature throughout the vessel.
6. Measure the final water temperature. (Example: The final temperature T2 = 21°C)
7. Calculate the microwave power output P in watts from above formula.

R-950A
13
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
Initial temperature............................................................................................. T1 = 11°C
Temperature after (47 + 2) = 49 sec................................................................. T2 = 21°C
Temperature difference Cold-Warm ............................................................... ∆T1 = 10°C
Measured output power
The equation is “P = 90 x ∆T”.................................................. P = 90 x 10°C = 900 Watts
JUDGMENT: The measured output power should be at least ±15 % of the rated output power.
CAUTION: 1°C CORRESPONDS TO 90 WATTS REPEAT MEASUREMENT IF THE POWER IS
INSUFFICIENT.
1000g
1000g
1000g
T1˚C T2˚C
Heat up for 49 sec.
B POWER TRANSFORMER TEST
WARNING: High voltages and large currents are present at the secondary winding and
filamentwindingofthepowertransformer.Itisverydangeroustoworknearthis
part when the oven is on. NEVER make any voltage measurements of the high-
voltage circuits, including the magnetron filament.
CARRY OUT 3D CHECKS.
Disconnect the leads to the primary winding of the power transformer. Disconnect the filament and
secondary winding connections from the rest of the HV circuitry. Using an ohmmeter, set on a low
range, it is possible to check the continuity of all three windings. The following readings should be
obtained:
a. Primary winding ................... approx. 1.0 Ω
b. Secondary winding............... approx. 66 Ω
c. Filament winding .................. less than 1Ω
If the reading obtained are not stated as above, then the power transformer is probably faulty and
should be replaced.
CARRY OUT 4R CHECKS.
HIGH VOLTAGE RECTIFIER TEST
CARRY OUT 3D CHECKS.
IsolatethehighvoltagerectifierassemblyfromtheHVcircuit.Thehighvoltagerectifier canbetested
using an ohmmeter set to its highest range. Connect the ohmmeter across the terminal B+C of the
high voltage rectifier and note the reading obtained. Reverse the meter leads and note this second
reading.Thenormalresistanceisinfiniteinonedirectionandmorethan100kΩintheotherdirection.
CARRY OUT 4R CHECKS.
ASYMMETRIC RECTIFIER TEST
CARRY OUT 3D CHECKS.
Isolate the high voltage rectifier assembly from the HV circuit. The asymmetric can be tested using
an ohmmeter set to its highest range across the terminals A+B of the asymmetric rectifier and note
the reading obtained. Reverse the meter leads and note this second reading. If an open circuit is
indicated in both direction then the asymmetric rectifier is good. If an asymmetric rectifier is shorted
in either direction, then the asymmetric rectifier is probably faulty and must be replaced with high
voltage rectifier. When the asymmetric rectifier is defective, check whether magnetron, high voltage
AB
C
D2 D1
ASYMMETRIC
RECTIFIER
HIGH VOLTAGE RECTIFIER
C HIGH VOLTAGE RECTIFIER ASSEMBLY TEST