Sharp Carousel R-395N Manuale di servizio - Pagina 14
Sfoglia online o scarica il pdf Manuale di servizio per Forno a microonde Sharp Carousel R-395N. Sharp Carousel R-395N 28. Microwave oven
Anche per Sharp Carousel R-395N: Manuale operativo e ricettario (40 pagine)
Stampa la pagina
R395N(S)
[12] L: KEY UNIT (MEMBRANE SWITCH) 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 2nd. interlock relay control switch
operates properly; that is the contacts are closed when the
door is closed and open when the door is open. If the 2nd.
interlock relay control switch is good, disconnect the flat rib-
bon cable that connects the key unit to the control unit and
make sure the 2nd. interlock relay control switch is closed
(either close the door or short the 2nd. interlock relay control
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 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 keypad is at fault.
[13] M: RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between the cabinet side terminal of the relay RY1 and the lower side terminal of the relay RY2 on the
power unit with an A.C. voltmeter. The meter should indicate 230 - 240 volts, if not check oven circuit.
RY1 and RY2 Relay Test
These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking 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.
RELAY SYMBOL
OPERATIONAL VOLTAGE
RY1
RY2
CARRY OUT 4R CHECKS.
[14] N: PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD (PWB) IS OPEN
To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary on the PWB, this foil pattern acts as a fuse. If the
foil pattern is open, follow the troubleshooting guide given below for repair.
CARRY OUT 3D CHECKS.
STEPS
The rated AC voltage is not present between the cabinet side terminal of the
1
relay RY1and the lower side terminal of the relay RY2.
2
The rated AC voltage is present to primary side of low voltage transformer.
3
Only pattern at "a" is broken.
4
Pattern at "a" and "b" are broken.
NOTE: *At the time of making these repairs, make a visual inspection of the varistor.
Check for burned damage and examine the transformer with a tester for the
presence of layer short-circuit (check the primary coil resistance). If any
abnormal condition is detected, replace the control unit.
CARRY OUT 4R CHECKS.
Approx. -12V D.C.
Oven lamp / Turntable motor / Cooling fan motor
Approx. -12V D.C.
Power transformer
OCCURRENCE
(G13)
G12
G11
G10
G9
G8
G7
G6
CONNECTED COMPONENTS
Check supply voltage and oven power cord.
Low voltage transformer or secondary circuit defective.
Check and repair.
*Insert jumper wire J1 and solder.
Replace the control unit.
8 – 5
G5
G4
G3
CAUSE OR CORRECTION
a
d
b
c
G2
G1