Sharp SMD3070ASY Service Manual page 15

SMD3070ASY
PROCEDURE
LETTER
12. Re-install the outer case (cabinet).
13. Reconnect the power supply cord after the outer case is installed.
14. Run the oven and check all function.
D DEFROST TEST
WARNING : The oven should be fully assembled before following procedure.
(1) Place one cup of water in the center of the tray in the oven cavity.
(2) Close the drawer, touch the Defrost pad. Then select Steaks/Chops by touching the number pad
2. And touch the number pad 5. (Now, weight 0.5lb is set.) And then touch the start pad.
(3) The oven is in Defrost cooking condition.
(4) The oven will operate as follows
(5) If improper operation is indicated, the control unit is probably defective and should be checked.
E PROCEDURES TO BE TAKEN WHEN THE FUSE IS OPEN
To protect the electronic circuits, this model is provided with a fuse added to the primary on the
Noise Filter Unit. In addition, there is a non-replaceable fuse on the Switching Power Supply.
1. Fuse check and repairs.
1) Disconnect the power supply cord.
2) Remove the outer case cabinet.
3) Open the door and block it open.
4) Discharge high voltage capacitor.
5) If the Fuse is blown, replace fuse. Also do filter test per procedure N.
6) Make a visual inspection of the varistors on Noise Unit as well as Switching Power Supply. Check for
burned damage. If the varistor on Switching Power Supply has burned damage, replace Switching
Power Supply. If the varistors on Noise Unit has burned damage replace Noise Filter Unit .
8) Reconnect all leads removed from components during testing.
9) Re-install the outer case (cabinet).
10) Reconnect the power supply cord after the outer case is installed.
11) Run the oven and check all functions.
2. Follow the troubleshooting guide given below, if power is not restored after above check and
repairs are finished.
1) Disconnect the power supply cord.
2) Remove the outer case cabinet.
3) Open the door and block it open.
4) Discharge high voltage capacitor.
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) Follow the troubleshooting guide given below for repair.
STEPS
1
2
3
TEST PROCEDURES
WEIGHT 1ST STAGE
LEVEL TIME
0.5lb 60% 20sec.
OCCURANCE
The rated AC voltage is NOT present
across Switching Power Supply CN101
(pins 1,3)
24Vdc is NOT present across
Switching Power Supply CN201
(pins 1,2)
24Vdc is present across
Power Unit CN-C (pins 1,5) /and/
The rated AC voltage is present across
Power Unit CN-A (pins 1,3)
COMPONENT TEST
2ND STAGE 3RD. STAGE
LEVEL TIME LEVEL
40% 20sec. 30%
CAUSE OR CORRECTION
No power to Switching Power Supply. Check
for wire breaks, open thermal cutouts.
Switching Power Supply not operating. Re-
place Switching Power Supply.
Normal power is being received by Power
Unit but Power Unit is not operating. Replace
Power Unit.
15
SMD2470ASY
TIME
45sec.