Sharp R-939(BK), Руководство по обслуживанию

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R939(W)
8 – 5
b) When touching the buttons, sometimes a button produces no signal.
2) Potentiometer
a) When rotating the potentiometer, the cooking mode can not be selected.
3) Encoder
a) When rotating the encoder, the cooking time or the weight of food can not be entered.
2. Control Panel
The following symptoms indicate a defective control unit. Before replacing the control unit, perform the Jog and Switch unit test (Procedure N) to
determine if control unit is faulty.
1) In connection with buttons
a) When touching the buttons, a certain group of buttons do not produce a signal.
b) When touching the buttons, no buttons produce a signal.
2) In connection with indicators
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light up.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits flicker.
3) 2-3 Other possible troubles caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
d) Proper temperature measurement is not obtained.
[14] Procedure N: JOG AND SWITCH UNIT TEST
If the display fails to clear when the STOP button (tact switch SW13) is depressed, first ver-
ify the wire harness is marking good contact, verify that the door sensing switch (stop
switch) operates properly; that is the contacts are closed when the door is closed and open
when the door is open. If the door sensing switch (stop switch) is good, disconnect the wire
harness that connects the Jog and Switch unit to the control unit and make sure the door
sensing switch is closed (either close the door or short the door sensing switch connecter).
Use the Jog and Switch unit matrix indicated on the control panel schematic and place a
jumper wire between the pins that correspond to the STOP button (tact switch SW13) mark-
ing momentary contact. If the control unit responds by clearing with a beep the Jog and
Switch 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 button does not respond, the above method may be used
(after clearing the control unit) to determine if the control unit or Jog and Switch unit is at
fault.
CARRY OUT 4R CHECKS.
J-6 J-5 J-2 J-1
J-3
J-4
J-8
J
-7
J-12
J-9
J-11
J-10
J-13
VR1
RSW1
A
B
3
1
2
C
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
SW9
SW10
SW13
SW12
SW11
SWITCH UNIT