R-360AM - Sharp Home Appliance Service Manual (repair manual). Page 7

R360AM - 7

Control Unit
Control unit consists of tact switches, LSI, power source
circuit, synchronizing signal circuit, ACL circuit, buzzer
circuit and indicator circuit.

The tact switches are composed of a matrix, signals
generated in the LSI are sent to the tact switches
through R6

0

-R6

2

. When a tact switches is touched, a

signal is completed through the tact switches and
passed back to the LSI through R8

1

-R8

3

 to perform the

function that was requested.

This LSI controls the key strobe signal, relay driving
signal for oven function and indicator signal.

This circuit generates voltages necessary in the control
unit.

 Symbol

Voltage

Application

VC

-5V

LSI(IC1)

The power source synchronizing signal is available in
order to compose a basic standard time in the clock

    OUTLINE OF TOUCH CONTROL PANEL

circuit. It accompanies a very small error because it
works on commercial frequency.

A circuit to generate a signals which resets the LSI to the
initial state when power is supplied.

The buzzer is responsive to signals from the LSI to emit
audible sounds (key touch sound and completion sound).

A switch to “tell” the LSI if the door is open or closed.

To drive the magnetron, fan motor, turntable motor and
light the oven lamp.

Indicator element is a Light-emitting diode.
Basically, a Light-emitting diode is triode having a
cathode  and an anode.
The Light-emitting diode has 4-digits, 8-segments are
used for displaying figures.

1. Disconnect oven from power supply and remove outer

case.

2. Discharge high voltage capacitor.
3. Discharge wire leads from the door sensing switch and

the oven cavity front flange.

4. Discharge the wire leads from panel components.
5. Make one (1) tab of the oven cavity front plate straight

holding the control panel assembly to the oven flange.

6. Slide the control panel assembly upward and remove it.
7. Now, individual components can be removed.
NOTE: 1. Before attaching a new key unit, wipe off remain-

ing adhesive on the control panel frame surfaces com-
pletely with a soft cloth soaked in alcohol.
2. When attaching the key unit to the control panel frame,
adjust the upper edge and right edge of the key unit to the
correct position of control panel frame.
3. Stick the key unit firmly to the control panel frame by
rubbing with soft cloth not to scratch.

CPU UNIT AND POWER UNIT
NOTE: When soldering the CPU unit and the power unit,

make sure both the CPU unit and the power unit are
parallel, as shown. Figure C-a.
Handle the CPU unit carefully so that the ribbon cable
does not come off, Because the ribbon cable is stuck on
the LCD and the printed wiring board only by a heated
paste.

CPU unit

Solder

These should be parallel

Power unit

Connector

Ribbon cable

Liquid Crystal

Display (LCD)

Printed wiring board

of CPU unit