DOWNLOAD Sharp R-770AM Service Manual ↓ Size: 537.34 KB | Pages: 27 in PDF or view online for FREE

Model
R-770AM
Pages
27
Size
537.34 KB
Type
PDF
Document
Service Manual
Brand
Device
Home Appliance / Microwave Oven
File
r-770am.pdf
Date

Sharp R-770AM Service Manual ▷ View online

 SERVICE MANUAL
SHARP CORPORATION
TABLE OF CONTENTS
Page
WARNING ................................................................................................................................................. 1
CAUTION, MICROWAVE RADIATION ..................................................................................................... 2
PRODUCT DESCRIPTION ....................................................................................................................... 2
APPEARANCE VIEW / WIRING/RE-WIRING .......................................................................................... 3
OPERATION SEQUENCE ........................................................................................................................ 4
FUNCTION OF IMPORTANT COMPONENTS ........................................................................................ 5
OUTPUT TEST PROCEDURE ................................................................................................................. 6
TEST PROCEDURES .......................................................................................................................... 7-8
TOUCH CONTROL PANEL ASSEMBLY ................................................................................................. 9
DESCRIPTION OF LSI ..................................................................................................................... 10-12
SERVICING ............................................................................................................................................ 13
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ............................................. 14-15
WIRING DIAGRAM ................................................................................................................................. 16
PICTORIAL DIAGRAM ........................................................................................................................... 17
CONTROL PANEL CIRCUIT .................................................................................................................. 18
PRINTED WIRING BOARD .................................................................................................................... 19
PARTS LIST ....................................................................................................................................  20-22
OVEN PARTS ......................................................................................................................................... 23
CONTROL PANEL PARTS ..................................................................................................................... 24
PACKING AND ACCESSORIES ............................................................................................................ 25
S9776R770AM//
MICROWAVE OVEN WITH
GRILL AND BOTTOM HEATER
MODELS
R-770A(B)/(W)M
R-770A(G)/(K)M
In interests of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
%
Kg
E
I
NL
GB
D
F
START/
AUTO MINUTE
TIME/WEIGHT
STOP/
CLEAR
MICROWAVE
POWER LEVEL
OVEN UM
CONVENIENCE FOODS
PIZZA
AUTO
COOK
AUTO
DEFROST
GRILL
DUAL
GRILL
Double Grill & Oven
D
900W
1
770AM -
 WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with following
parts will result in electrocution:-
High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier assembly, High voltage
harness.
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
The high-voltage capacitor remains charged about 60 seconds after the oven has been switched off. Wait for
60 seconds and then short-circuit the connection of the high-voltage capacitor (that is, of the connecting lead
of the high-voltage rectifier) against the chassis using a screwdriver with an insulated handle.
Sharp recommend that wherever possible, fault-finding is carried out with the supply disconnected.
In some cases, it may be necessary to connect the supply with  the cover removed to carry out fault
investigation in the control circuitry.  In such cases, the high voltage circuit should be disabled as
described below to reduce the hazards:-
Carry out 3D checks (see above).
Disconnect the supply leads from the high voltage transformer, making a note of the polarity.  Insulate the
connectors, ensuring they are positioned away from the transformer and fastened there.
Connect any relevant test equipment e.g. voltmeter.
Reconnect the oven to the supply, then close the door.
Note the results of the test, taking care to keep clear of the operational oven.
Carry out 3D checks (see above).
Reconnect the leads to the transformer.  Take care to observe correct polarity.
Carry out 4R checks (see below).
Microwave ovens should not be used without a load.   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 one
(1) minute, set the power level to HIGH (100%) and push the start key. When the one (1) minute has elapsed
(timer at zero) carefully check that the water is now hot.
AFTER REPAIR 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.
When all service work is completed, and the oven is fully assembled, the microwave power output should
be checked and microwave leakage test carried out.
IMPORTANT: If the oven becomes inoperative because of a blown fuse F8A in the 1st latch switch -
monitor switch circuit, check the 1st latch switch and monitor switch before replacing the fuse F8A.
WARNING
2
770AM -
CAUTION/WARNING
CAUTION
MICROWAVE RADIATION
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
antenna while the device is energized.
WARNING
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
microwave exposure, by themselves, or when they are
damaged, loosened or removed.
SPECIFICATION
ITEM
DESCRIPTION
Power Requirements
230/240 Volts
50 Hertz
Single phase, 3 wire earthed
Power Consumption
Microwave cooking
1.6 kW  Approx. 7.2 A
Top Grill mode
1.25 kW
Approx. 5.2 A
Grill cooking
Bottom Heater mode
0.85 kW
Approx. 3.5 A
Top and Bottom  mode
2.05 kW
Approx. 8.5 A
Dual cooking
Micro and Top Grill
2.8 kW
12A Approx.
Micro and Bottom Heater
2.3 kW
10A Approx.
Power Output
900 W nominal of RF microwave energy (measured by method of IEC 705)
Operating fequency 2450 MHz
Grill heating element Power Output (Top Grill)
1200 W (600 W x 2)
Bottom heating element Power Output
900W
Case Dimensions
Width
520 mm
Height
309 mm including foot
Depth
436 mm
Cooking Cavity Dimensions
Width
349 mm
Height
207 mm
Depth
357 mm
Turntable diameter
325 mm
Control Complement
Jog Touch Control System
Clock (1:00 - 12:59) / Timer (0 - 90 minutes)
Microwave Power for Variable Cooking
 Repetition Rate;
100% ...................................... Full power throughout the cooking time
70% ........................................................  approx. 70% of FULL Power
50% ........................................................  approx. 50% of FULL Power
30% ........................................................  approx. 30% of FULL Power
10% ........................................................  approx. 10% of FULL Power
FUNCTION KEYS:
LESS (
)/MORE (
) keys, WEIGHT CONVERSION key
TIMER key, PIZZA key, CONVIENIENCE FOODS key,
AUTO COOK key, AUTO DEFROST key, MICROWAVE POWER LEVEL key
DUAL key, GRILL key, OVEN key, STOP / CLEAR key,
AUTO MINUTE  / START key, CLOCK key, TIME/WEIGHT knob
Set Weight
Approx. 19 kg
WARNING
THIS APPLIANCE MUST BE EARTHED
THE WIRES IN THIS MAINS LEAD ARE COLOURED IN
ACCORDANCE WITH THE FOLLOWING CODE:
GREEN-AND-YELLOW : EARTH        BLUE : NEUTRAL        BROWN : LIVE
If the mains lead is replaced, only part number QACCBA004URE1 should be used.
PRODUCT DESCRIPTION
3
770AM -
OVEN
1. Control panel
2. Oven lamp
3. Grill heating element (Top Grill)
4. Door opening button
5. Waveguide cover
6. Oven cavity
7. Turntable motor shaft
8. Grill heating element
(Bottom Heater)
9. Door seals and sealing surfaces
10.Ventilation openings
11.Outer cabinet
12.Power supply cord
1
4
10
11
12
5
6
7
2
3
8
9
10
Turntable 
Turntable
support 
High rack
Low rack
Turntable 
motor shaft 
Bottom 
heater
1. Ensure that the bottom heater is in the lowest
position as shown the figure. As it is possible to
move it up and down to help with cleaning.
2. Place the turntable support over the turntable
motor shaft on the floor of the cavity.
3. Then place the turntable on to the turntable sup-
port.
10
11
12
WARNING: Before carrying out any work carry out 3D checks
1) Disconnect the supply.
2) Door opened, and wedged open.
3) Discharge high voltage capacitor.
RE-WIRING
Ensure the following:
1.
Wires must not touch:
a)
High voltage parts.
(Magnetron, high voltage transformer, high voltage capacitor and high voltage rectifier assembly)
b)
Parts that become hot.
(Heating elements, oven lamp, oven cavity magnetron and high voltage transformer)
c)
Sharp edges.
(Bottom plates, oven cavity, waveguide flange, chassis support and other metallic parts)
d)
Movable parts.
(Fan blade, any motor, switch, switch lever and open button)
2.
Positive lock connectors are fitted correctly.  Ensure the locking pin is located correctly.
3.
Wires are connected correctly as per pictorial diagram.
4.
No wire leads are trapped by the outer wrap.
WIRING / RE-WIRING
APPEARANCE VIEW
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  • DOWNLOAD Sharp R-770AM Service Manual ↓ Size: 537.34 KB | Pages: 27 in PDF or view online for FREE
  • Here you can View online or download the Service Manual for the Sharp R-770AM in PDF for free, which will help you to disassemble, recover, fix and repair Sharp R-770AM Microwave Oven. Information contained in Sharp R-770AM Service Manual (repair manual) includes:
  • Disassembly, troubleshooting, maintenance, adjustment, installation and setup instructions.
  • Schematics, Circuit, Wiring and Block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Exploded View and Parts List.