Sharp R-1505F Service Manual page 21

PROCEDURE
LETTER
N RELAY TEST
1. Disconnect the power supply cord, and then remove outer case. Refer to procedure of " HOOD
EXHAUST LOUVER REMOVAL ", " REMOVAL OF OVEN FROM WALL " and " OUTER CASE
REMOVAL ".
2. Open the door and block it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. Remove the hood intake duct R.
5. Disconnect the leads to the primary of the power transformer.
6. Ensure that these leads remain isolated from other components and oven chassis by using insulation
tape.
7. After that procedure, re-connect the power supply cord.
8. Check voltage between normal open terminal of the relay RY2 and the normal open terminal of the
relay RY1 on the control unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
RY1, RY2, RY3, RY4, RY5 and RY6 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.
RELAY SYMBOL
RY1
RY2(COOK)
RY3
RY4
RY5
RY6
9. Disconnect the power supply cord.
10. Open the door and block it open.
11. To discharge high voltage capacitor, wait for 60 seconds.
12. Reconnect all leads removed from components during testing.
13. Re-install the hood intake duct R.
14. Re-install the outer case (cabinet).
15. Reconnect the power supply cord after the outer case is installed.
16. Run the oven and check all functions.
O DEFROST CENTER TEST
(1) Open the door.
(2) Place one cup of water in the center of the turntable tray in the oven cavity.
(3) Touch the " STEAKS/CHOPS " pad once.
(4) Close the door.
(5) Touch the " START " button.
(6) The oven is in Defrost center cooking condition.
(7) The oven will operate as follows.
Menu
Steaks/Chops
0.5lbs
(8) If improper operation is indicated, the control unit is probably defective and should be checked.
P FOIL PATTERN ON THE PRINTED WIRING BOARD TEST
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.
TEST PROCEDURES
DC. voltage indicated ....................Defective relay.
DC. voltage not indicated .............. Check diode which is connected to the relay coil. If diode
OPERATIONAL VOLTAGE
Approx. 26.6V D.C.
Approx. 26.0V D.C.
Approx. 26.6V D.C.
Approx. 26.6V D.C.
Approx. 26.6V D.C.
Approx. 26.6V D.C.
1ST STAGE
LEVEL TIME
60% 57sec.
COMPONENT TEST
is good, control unit is defective.
CONNECTED COMPONENTS
Oven lamp / Fan motor / Turntable motor
Power transformer
Hood motor
Hood motor
Hood lamp
Hood lamp
2ND STAGE
LEVEL TIME
40% 17sec.
19
R-1500
R-1501
R-1505
R-1506