Sharp R-86STMA (serv.man8) Service Manual ▷ View online
R86STMA
8 – 5
[14] N: KEY UNIT TEST
If the display fails to clear when the STOP/CLEAR pad is
depressed, first verify the ribbon cable is making good con-
tact, 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, 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 control panel schematic and place a
jumper wire between the pins that correspond to 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.
depressed, first verify the ribbon cable is making good con-
tact, 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, 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 control panel schematic and place a
jumper wire between the pins that correspond to 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.
CARRY OUT 4R CHECKS.
[15] O: RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 5 and 7 of the 4 pin connector (E) on the control unit with an A.C. voltmeter. The meter
should indicate 230-240 volts, if not check oven circuit.
should indicate 230-240 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill operation, convection operation or dual operation.
DC. voltage indicated ................................... Defective relay.
DC. voltage not indicated ............................. Check diode which is connected to the relay coil. If diode is good, control unit is defective.
CARRY OUT 4R CHECKS.
[16] P: PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD (PWB) IS OPEN
BOARD (PWB) IS OPEN
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
NOTE: *At the time of these repairs, make a visual inspection of the varistor for burn-
ing damage and examine the transformer with tester for the presence of layer
short circuit (check primary coil resistance).
short circuit (check primary coil resistance).
If any abnormal condition is detected, replace the control unit.
CARRY OUT 4R CHECKS.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
APPROX. 18.0V D.C.
Oven lamp / Turntable motor
RY2
APPROX. 18.0V D.C.
High voltage transformer
RY3
APPROX. 24.0V D.C.
Grill (Top) heating element
RY4
APPROX. 24.0V D.C.
Bottom heating element
RY5
APPROX. 24.0V D.C.
Touch control transformer
RY6
APPROX. 24.0V D.C.
Fan motor
RY7
APPROX. 24.0V D.C.
Convection motor
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between Pin Nos. 5 and 7 of
the 4-pin connector (E).
the 4-pin connector (E).
Check supply voltage and oven power cord.
2
The rated AC voltage is present at primary side of low voltage
transformer.
transformer.
Low voltage transformer or secondary circuit defective.
Check and replace the touch control transformer or the control unit.
Check and replace the touch control transformer or the control unit.
3
Pattern at “a” is broken.
Replace the control unit.
(CARRY OUT 3D CHECKS BEFORE REPAIR)
(CARRY OUT 3D CHECKS BEFORE REPAIR)
G2
G3
G4
G5
G6
G7
G8
G12
G11
G10
G9
G1
STOP
CLEAR
(WEIGHT)
OVEN
FRESH
COMBI
10min.
KITCHEN TIMER
(WEIGHT)
REHEAT
SOUP
REHEAT
TEA/COFFEE
AUTO
COOK
MELTED
BUTTER
CONV.
(ºC)
info
(TIME)
REHEAT
SAUCE
PIZZA
GRILL
1min.
START
AUTO MINUTE
(TIME)
TAKEAWAY
REHEAT
EASY
RISOTTO
MICRO
POWER
EXPRESS
DEFROST
EXPRESS
COOK
10sec.
a
7
JP0
S1
CN-A
R86STMA
8 – 5
[14] N: KEY UNIT TEST
If the display fails to clear when the STOP/CLEAR pad is
depressed, first verify the ribbon cable is making good con-
tact, 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, 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 control panel schematic and place a
jumper wire between the pins that correspond to 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.
depressed, first verify the ribbon cable is making good con-
tact, 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, 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 control panel schematic and place a
jumper wire between the pins that correspond to 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.
CARRY OUT 4R CHECKS.
[15] O: RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 5 and 7 of the 4 pin connector (E) on the control unit with an A.C. voltmeter. The meter
should indicate 230-240 volts, if not check oven circuit.
should indicate 230-240 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill operation, convection operation or dual operation.
DC. voltage indicated ................................... Defective relay.
DC. voltage not indicated ............................. Check diode which is connected to the relay coil. If diode is good, control unit is defective.
CARRY OUT 4R CHECKS.
[16] P: PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD (PWB) IS OPEN
BOARD (PWB) IS OPEN
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
NOTE: *At the time of these repairs, make a visual inspection of the varistor for burn-
ing damage and examine the transformer with tester for the presence of layer
short circuit (check primary coil resistance).
short circuit (check primary coil resistance).
If any abnormal condition is detected, replace the control unit.
CARRY OUT 4R CHECKS.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
APPROX. 18.0V D.C.
Oven lamp / Turntable motor
RY2
APPROX. 18.0V D.C.
High voltage transformer
RY3
APPROX. 24.0V D.C.
Grill (Top) heating element
RY4
APPROX. 24.0V D.C.
Bottom heating element
RY5
APPROX. 24.0V D.C.
Touch control transformer
RY6
APPROX. 24.0V D.C.
Fan motor
RY7
APPROX. 24.0V D.C.
Convection motor
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between Pin Nos. 5 and 7 of
the 4-pin connector (E).
the 4-pin connector (E).
Check supply voltage and oven power cord.
2
The rated AC voltage is present at primary side of low voltage
transformer.
transformer.
Low voltage transformer or secondary circuit defective.
Check and replace the touch control transformer or the control unit.
Check and replace the touch control transformer or the control unit.
3
Pattern at “a” is broken.
Replace the control unit.
(CARRY OUT 3D CHECKS BEFORE REPAIR)
(CARRY OUT 3D CHECKS BEFORE REPAIR)
G2
G3
G4
G5
G6
G7
G8
G12
G11
G10
G9
G1
STOP
CLEAR
(WEIGHT)
OVEN
FRESH
COMBI
10min.
KITCHEN TIMER
(WEIGHT)
REHEAT
SOUP
REHEAT
TEA/COFFEE
AUTO
COOK
MELTED
BUTTER
CONV.
(ºC)
info
(TIME)
REHEAT
SAUCE
PIZZA
GRILL
1min.
START
AUTO MINUTE
(TIME)
TAKEAWAY
REHEAT
EASY
RISOTTO
MICRO
POWER
EXPRESS
DEFROST
EXPRESS
COOK
10sec.
a
7
JP0
S1
CN-A
R86STMA
8 – 5
[14] N: KEY UNIT TEST
If the display fails to clear when the STOP/CLEAR pad is
depressed, first verify the ribbon cable is making good con-
tact, 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, 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 control panel schematic and place a
jumper wire between the pins that correspond to 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.
depressed, first verify the ribbon cable is making good con-
tact, 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, 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 control panel schematic and place a
jumper wire between the pins that correspond to 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.
CARRY OUT 4R CHECKS.
[15] O: RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 5 and 7 of the 4 pin connector (E) on the control unit with an A.C. voltmeter. The meter
should indicate 230-240 volts, if not check oven circuit.
should indicate 230-240 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill operation, convection operation or dual operation.
DC. voltage indicated ................................... Defective relay.
DC. voltage not indicated ............................. Check diode which is connected to the relay coil. If diode is good, control unit is defective.
CARRY OUT 4R CHECKS.
[16] P: PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD (PWB) IS OPEN
BOARD (PWB) IS OPEN
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
NOTE: *At the time of these repairs, make a visual inspection of the varistor for burn-
ing damage and examine the transformer with tester for the presence of layer
short circuit (check primary coil resistance).
short circuit (check primary coil resistance).
If any abnormal condition is detected, replace the control unit.
CARRY OUT 4R CHECKS.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
APPROX. 18.0V D.C.
Oven lamp / Turntable motor
RY2
APPROX. 18.0V D.C.
High voltage transformer
RY3
APPROX. 24.0V D.C.
Grill (Top) heating element
RY4
APPROX. 24.0V D.C.
Bottom heating element
RY5
APPROX. 24.0V D.C.
Touch control transformer
RY6
APPROX. 24.0V D.C.
Fan motor
RY7
APPROX. 24.0V D.C.
Convection motor
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between Pin Nos. 5 and 7 of
the 4-pin connector (E).
the 4-pin connector (E).
Check supply voltage and oven power cord.
2
The rated AC voltage is present at primary side of low voltage
transformer.
transformer.
Low voltage transformer or secondary circuit defective.
Check and replace the touch control transformer or the control unit.
Check and replace the touch control transformer or the control unit.
3
Pattern at “a” is broken.
Replace the control unit.
(CARRY OUT 3D CHECKS BEFORE REPAIR)
(CARRY OUT 3D CHECKS BEFORE REPAIR)
G2
G3
G4
G5
G6
G7
G8
G12
G11
G10
G9
G1
STOP
CLEAR
(WEIGHT)
OVEN
FRESH
COMBI
10min.
KITCHEN TIMER
(WEIGHT)
REHEAT
SOUP
REHEAT
TEA/COFFEE
AUTO
COOK
MELTED
BUTTER
CONV.
(ºC)
info
(TIME)
REHEAT
SAUCE
PIZZA
GRILL
1min.
START
AUTO MINUTE
(TIME)
TAKEAWAY
REHEAT
EASY
RISOTTO
MICRO
POWER
EXPRESS
DEFROST
EXPRESS
COOK
10sec.
a
7
JP0
S1
CN-A
R86STMA
8 – 5
[14] N: KEY UNIT TEST
If the display fails to clear when the STOP/CLEAR pad is
depressed, first verify the ribbon cable is making good con-
tact, 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, 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 control panel schematic and place a
jumper wire between the pins that correspond to 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.
depressed, first verify the ribbon cable is making good con-
tact, 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, 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 control panel schematic and place a
jumper wire between the pins that correspond to 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.
CARRY OUT 4R CHECKS.
[15] O: RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 5 and 7 of the 4 pin connector (E) on the control unit with an A.C. voltmeter. The meter
should indicate 230-240 volts, if not check oven circuit.
should indicate 230-240 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill operation, convection operation or dual operation.
DC. voltage indicated ................................... Defective relay.
DC. voltage not indicated ............................. Check diode which is connected to the relay coil. If diode is good, control unit is defective.
CARRY OUT 4R CHECKS.
[16] P: PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD (PWB) IS OPEN
BOARD (PWB) IS OPEN
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
NOTE: *At the time of these repairs, make a visual inspection of the varistor for burn-
ing damage and examine the transformer with tester for the presence of layer
short circuit (check primary coil resistance).
short circuit (check primary coil resistance).
If any abnormal condition is detected, replace the control unit.
CARRY OUT 4R CHECKS.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
APPROX. 18.0V D.C.
Oven lamp / Turntable motor
RY2
APPROX. 18.0V D.C.
High voltage transformer
RY3
APPROX. 24.0V D.C.
Grill (Top) heating element
RY4
APPROX. 24.0V D.C.
Bottom heating element
RY5
APPROX. 24.0V D.C.
Touch control transformer
RY6
APPROX. 24.0V D.C.
Fan motor
RY7
APPROX. 24.0V D.C.
Convection motor
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between Pin Nos. 5 and 7 of
the 4-pin connector (E).
the 4-pin connector (E).
Check supply voltage and oven power cord.
2
The rated AC voltage is present at primary side of low voltage
transformer.
transformer.
Low voltage transformer or secondary circuit defective.
Check and replace the touch control transformer or the control unit.
Check and replace the touch control transformer or the control unit.
3
Pattern at “a” is broken.
Replace the control unit.
(CARRY OUT 3D CHECKS BEFORE REPAIR)
(CARRY OUT 3D CHECKS BEFORE REPAIR)
G2
G3
G4
G5
G6
G7
G8
G12
G11
G10
G9
G1
STOP
CLEAR
(WEIGHT)
OVEN
FRESH
COMBI
10min.
KITCHEN TIMER
(WEIGHT)
REHEAT
SOUP
REHEAT
TEA/COFFEE
AUTO
COOK
MELTED
BUTTER
CONV.
(ºC)
info
(TIME)
REHEAT
SAUCE
PIZZA
GRILL
1min.
START
AUTO MINUTE
(TIME)
TAKEAWAY
REHEAT
EASY
RISOTTO
MICRO
POWER
EXPRESS
DEFROST
EXPRESS
COOK
10sec.
a
7
JP0
S1
CN-A
Display
