Read Sharp R-765M (serv.man7) Service Manual online
R-765M - 14
N
RELAY TEST
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable
is making good contact, verify that the stop switch operates properly; that is the contacts are closed
when the door is closed and open when the door is open. If the stop switch is good, press stop/clear
pad while checking continuity between pins 5 and 12 of connector CN-G. If no continuity is measured,
the key unit is faulty and should be replaced. If continuity is measured, the control unit is faulty and
should be replaced. If a specific pad does not respond, the above method may be used. Disconnect
the flat ribbon cable that connects the key unit to the control unit and make sure the stop switch is closed
(either close the door or short the stop switch connector). Use the Key unit matrix indicated on the
STOP/CLEAR pad making momentary contact. If the control unit responds by clearing with a beep the
key unit is faulty and must be replaced. If the control unit does not respond, it is a faulty and must be
replaced. If a specific pad does not respond, the above method may be used (after clearing the control
unit) to determine if the control unit or key pad is at fault.
is making good contact, verify that the stop switch operates properly; that is the contacts are closed
when the door is closed and open when the door is open. If the stop switch is good, press stop/clear
pad while checking continuity between pins 5 and 12 of connector CN-G. If no continuity is measured,
the key unit is faulty and should be replaced. If continuity is measured, the control unit is faulty and
should be replaced. If a specific pad does not respond, the above method may be used. Disconnect
the flat ribbon cable that connects the key unit to the control unit and make sure the stop switch is closed
(either close the door or short the stop switch connector). Use the Key unit matrix indicated on the
STOP/CLEAR pad making momentary contact. If the control unit responds by clearing with a beep the
key unit is faulty and must be replaced. If the control unit does not respond, it is a faulty and must be
replaced. If a specific pad does not respond, the above method may be used (after clearing the control
unit) to determine if the control unit or key pad is at fault.
M
KEY UNIT TEST
L
TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc.
Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with
only a voltmeter and ohmmeter.
In this service manual, the touch control panel assembly is divided into two units, Control Unit and
Key Unit, and also the control unit is divided into two units, CPU Unit and Power Unit, and
troubleshooting by unit replacement is described according to the symptoms indicated.
1. Key Unit
Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with
only a voltmeter and ohmmeter.
In this service manual, the touch control panel assembly is divided into two units, Control Unit and
Key Unit, and also the control unit is divided into two units, CPU Unit and Power Unit, and
troubleshooting by unit replacement is described according to the symptoms indicated.
1. Key Unit
The following symptoms indicate a defective key unit. Replace the key unit.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
2. Control Unit
The following symptoms indicate a defective control unit. Replacing the control unit.
2-1 In connection with pads.
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
2-3 Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
b) Clock does not operate properly.
c) Cooking is not possible.
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
G12
G11
G10
G 9
G 1
G 2
G 3
G 4
G 5
G 6
G 7
G 8
ROAST BEEF / LAMB
WHOLE POULTRY
CHICKEN QUARTERS
ROAST PORK
PASTA DISH
RISOTTO
GRATIN
MEAT JOINT
ROAST POULTRY
MICROWAVE
POWER LEVEL
GRILL
DOWN
LESS
MORE
UP
KITCHEN
TIMER
CLEAR
AUTO MINUTE
STOP
START
DELAY START
CLOCK SET
KG / LB
CONVERSION
AUTO
COOK
DUAL GRILL
1. CARRY OUT 3D CHECKS.
2. Disconnect the leads from the primary of the high voltage transformer. Make sure that the leads
2. Disconnect the leads from the primary of the high voltage transformer. Make sure that the leads
remain isolated from other oven components and chassis. (Use insulation tape if necessary.)
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