Sharp R-8380 Service Manual page 21

R-8380
TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER
COMPONENT TEST
CHECKING CONTROL UNIT
(1) Disconnect oven from power supply and remove outer case.
(2) Discharge the high voltage capacitor.
(3) Disconnect the wire leads from the cook relay.
(4) Disconnect the sensor :onnector.
(5) Then connect the duml .y resistor circuit (see fig.) to the sensor connector of control panel.
(6) Reconnect the oven to the power supply
and check the sensor cook operation
proceed as
follows:
6-l. Touch SENSOR COOK pad and number 2 pad.
6-2. The control panel is in the sensor cooking operation.
6-3. After approximately 20 seconds, push plunger of select switch.
This condition is same as judgement by AH sensor.
6-4. After approximately 3 seconds, cooking operation turns off, an audible signal will
sound, and the display will then revert to the time of day.
If the above is not the case, the control unit is probably defective.
If the above is proper, the AH sensor is probably defective.
NC
T, Conncc1or NC'
NO
07 Con,,0 ""8'
0
C3W~EC'O~
COM
Rl.R2 10011
f
? 1% 1 '2W
R3 10kli t 5% 1 '4W
R4
12klZ I 5% 1 4w
Sensor Dummy Resistor Circuit
CRD82Q09U)
Q
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD(PWB) IS OPEN.
e
*
To protect the electronic circuits, this model is provided with a fine foil pattern added to the
primary on the PWB, and this fine pattern service as a substitute coil. If the foil pattern is open,
follow the troubleshooting guide given below for repair.
Problem: POWER ON, indicator does not light up.
STEPS /
OCCURANCE
1 ' The rated voltage is not applied to POWER terminal / Check supply voltage and oven main unit.
I
f
/ of CPU connector (CN-A)
I
/
2
~ The rated voltage is applied to primary side of power / Power transformer or secondary circuit defective. /
I transformer.
/ Check and reoair.
3
1 Only pattern at "a" is broken. / 'Insert jumper wire 1 and solder.
1
~ 4
1 Pattern at "a" and "b" are broken. j 'Insert the coil RCILF2003YAZZ between "c" and /
/ "d"
NOTE:' At the time of these repairs, make visual in-
spection of the varistor for burning damage
and examine the transformer with tester for the
presence of layer short-circuit (check primary
coil resistance).
If any abnormal condition is detected, replace
the defective parts.
(04U)
20