R-8740 (serv.man7). Troubleshooting guide — Sharp Home Appliance Service Manual (repair manual)

Model
R-8740 (serv.man7)
Pages
2 Few pages! See other manuals at the bottom of the first or last page.
Size
450.45 KB
Type
PDF
Document
Service Manual
Brand
Device
Home Appliance / Microwave Oven / Troubleshooting guide
File
r-8740-sm7.pdf
Date

View Sharp R-8740 (serv.man7) Service Manual online

R-8740M  - 12
       PROBLEM
Fuse F2 F8A blows when the door is opened.
Home fuse blows when power cord is plugged into wall outlet.
Fuse F1 15A blows when power cord is plugged into wall
outlet.
":0" does not appear in display when power cord is plugged
into wall outlet.
Display does not operate properly when STOP/CLEAR key is
touched.
Oven lamp does not light when door is opened. (Display
operates.)
Oven does not start when the START key is touched. (Display
operates.)
Oven lamp does not light And turntable motor does not
operate.
Fan motor does not operate. (Oven lamp lights.)
Convection fan motor does not operate. (Oven lamp lights.)
Turntable motor does not operate. (Oven lamp lights.)
Oven or any electrical parts (except fan motor) does not stop
when cooking time is 0 or STOP/CLEAR key is touched.
Oven stops after about 4 minutes since START key is touched.
(Except Microwave and Dual Cook modes)
Display operates properly but all electrical parts do not oper-
ate.
The oven stops 1 minute after starting.
Oven goes into cook cycle but shuts down before end of
cooking cycle.
After cooking, the temperature of oven cavity is higher than
104˚C but the fan motor does not operate.
Oven seems to be operating but little or no heat is produced in
oven load. (Microwave power control is set at HIGH)
Oven does not seem to be operating properly during variable
cooking condition. (Oven operates properly at HIGH)
Oven goes into cook cycle but shuts down before end of
cooking cycle.
Convection cooking mode does not heat.
Oven seems to be operate when the temperature in the oven
cavity is lower or higher than preset one.
Grill heating element does not heat.
Convection heating does not stop when the temperature of
oven cavity is higher than 210˚C or it stop to heat when the
temperature of oven cavity is lower than 210˚C
Oven goes into cook cycle but shuts down before end of
cooking cycle.
Oven seems to be operating but little or no heat is produced in
oven load. (Microwave power does not seem to be generated
properly)
Oven seems to be operating but the temperature of oven cavity
is lower or higher than preset one.
Convection heating element does not heat.
Grill heating does not heat.
TEST PROCEDURE
OFF
CONDITION
DUAL COOKING
CONDITION
(MICRO./GRILL)
MAGNETRON
HIGH VOLTAGE  TRANSFORMER
H.V. RECTIFIER ASSEMBLY
H.V. HARNESS
HIGH VOLTAGE CAPACITOR
MONITORED LATCH SWITCH
STOP SWITCH
MONITOR SWITCH
THERMAL CUT-OUT 150
˚C TC1
THERMAL CUT-OUT 125
˚C TC2
TURNTABLE MOTOR
FAM NOTOR
CONVECTION FAN MOTOR
NOISE FILTER
 A   B   C
  D E E E G G H H H I
COOKING
CONDITION
(COMMON  MODE)
MICROWAVE
COOKING
CONDITION
CONVECTION
COOKING
CONDITION
DUAL COOKING
CONDITION
(COMMON  MODE)
DUAL COOKING
CONDITION
(MICRO./CONV.)
GRILL
COOKING
CONDITION
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
TROUBLESHOOTING GUIDE
R-8740M  - 13
J    K M M N
FUSE  20A
FUSE F2 F8A
GRILL HEATING ELEMENT (TOP)
GRILL HEATING ELEMENT (BOTTOM)
THERMISTOR
POWER SUPPLY CORD
SHORTED WIRE HARNESS
OPENED WIRE HARNESS
OVEN LAMP OR SOCKET
TC TRANSFORMER
TOUCH CONTROL PANEL
BLOCKED VENTILATION OPENINGS
WRONG OPERATION
MIS-ADJUSTMENT OF SWITCHES
HOME FUSE OR BREAKER
NO POWER AT WALL OUTLET
BLOCKED CONVECTION FAN
BLOCKED COOLING FAN
RELAY (RY1, 2, 3, 4, 5, 7)
FOIL PATTERN
KEY UNIT
O
P Q R
TROUBLESHOOTING GUIDE
Page of 2
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Here you can view online or download Sharp R-8740 (serv.man7) Service Manual in pdf. This Service Manual can help you recover, restore, fix, disassemble and repair Sharp R-8740 (serv.man7) Microwave Oven. Information contained in Sharp R-8740 (serv.man7) service manual (repair manual) typically includes:

  • Disassembly, troubleshooting, programming, maintenance, remote, adjustment, installation and setup instructions.
  • Schematics, wiring and block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Parts list (bill of materials).