Sharp R-3H57 Service Manual page 16

R-3H57
PROCEDURE
LETTER
1. Key Unit
The following symptoms indicate a defective key unit. Replace the key unit.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
2. Control Panel.
The following symptoms indicate a defective control unit. Replace the control unit.
2-1 In connection with pads.
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
2-2 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.
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.
2-3 Other possible problems 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.
K KEY UNIT TEST
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon is making
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 flat ribbon that connects the key unit to
the control unit and make sure the door sensing switch is closed (either close the door or short the door
sensing 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 key pad is at fault.
TEST PROCEDURES (CONT'D)
G7
G8
5 4
G9
0 9
G10
MEMORY POWER
G11
1 LEVEL
INSTANT
MEMORY
COOK
G12
2
START
COMPONENT TEST
G4
G6 G5
3 2 1
7
8
6
Jacket
AUTO EASY
Potato
START DEFROST
Fish
RICE
DESSERTS
Fillets
PASTA
14
G3 G2 G1
REHEAT HELP TIMER
STOP
Reheat
MEAT
Beverage
CLEAR
VEGE-
CLOCK
TABLES
LESS
Fresh
Vegetables
MORE
KEY UNIT