Sharp R1481 Manual

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TEST PROCEDURES
PROCEDURE
LETTERCOMPONENT TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power transformer.
5. Ensure that these leads remain isolated from other components and oven chassis by using insulation
tape.
6. After that procedure, re-connect the power supply cord.
7. Remove the outer case and check voltage between Pin No. 7 of the...

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TEST PROCEDURES
PROCEDURE
LETTERCOMPONENT TEST
STEPS OCCURRENCE CAUSE OR CORRECTION
1 Only pattern at a is broken. *Insert jumper wire J1 and solder.
2 Pattern at a and b are broken. *Insert the coil RCILF2003YAZZ between c and d.
5) Make a visual inspection of the varistor.
Check for burned damage and examine
the transformer with a tester for the
presence of layer short-circuit (check
the primary coil resistance which is
approximately 192W ± 15%). If any
abnormal condition is...

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TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in
order to compose a basic standard time in the clock
circuit. It incorporates a very small error because it works
on commercial frequency.
4) ACL Circuit
A circuit to generate a signals which resetting the LSI to
the initial state when power is applied.
5) Buzzer Circuit
The buzzer responds to signals from the LSI to emit
audible sounds...

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DESCRIPTION OF LSI
LSI(IZA876DR)
The I/O signals of the LSI(IZA876DR) are detailed in the following table.
Pin No. Signal I/O Description
1 VCC IN Connected to GND.
2 VEE IN
Anode (segment) of Fluorescent Display illumination voltage: -31V.
Vp voltage of power source circuit input.
3 AVSS IN
Power source voltage:-5V.
VC voltage of power source circuit input.
4 VREF IN
Reference voltage input terminal.
A reference voltage applied to the A/D converter in the LSI. Connected to...

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22 P44 OUT Terminal not used.
23 P43 OUT
Signal to sound buzzer.
A: key touch sound.
B: Completion sound.
C: When the temperature of the oven cavity reaches
the preset temperature in the preheating mode,
or when the preheating hold time (30 minutes) is
elapsed.
24 P42 IN Terminal not used.
25 INT1 IN
Signal to synchronize LSI with commercial power source frequency.
This is the basic timing for all real time processing of LSI.
26 P40 IN Connected to VC.
27 RESET IN
Auto clear...

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Pin No. Signal I/O Description
ß(60Hz)
GND
VP
41-44 P17-P14 OUTDigit selection signal.
Signal similar to P23.
45-48 P13-P10 OUT
Segment data signals.
The relation between signals and indicators are as follows:
Signal Segment Signal Segment
P13 ............... P15 P03 ................ P7
P12 ............... P14 P02 ................ P6
P11 ............... P13 P01 ................ P5
P10 ............... P12 P00 ................ P4
P07 ............... P11 P37 ................ P3
P06...

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1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the
circuits. When handling these parts, the following
precautions should be strictly followed. CMOS LSI have
extremely high impedance at its input and output
terminals. For this reason, it is easily influenced by the
surrounding high voltage power source, static electricity
charge in clothes, etc, and sometimes it is not fully
protected by the built-in protection circuit.
In order to...

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Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may
result in severe, possibly fatal, electric shock.
(Example)
High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly,  High Voltage Harness etc..
WARNING:Avoid possible exposure to microwave energy. Please follow the instructions below before
operating the oven.
WARNING AGAINST HIGH VOLTAGE:
COMPONENT REPLACEMENT AND ADJUSTMENT...

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REMOVAL OF OVEN FROM WALL (Two persons recommended to remove the oven)
1. Disconnect the power supply cord, and uncoil the power
supply cord.
2. Remove the turntable tray and support from the oven cavity.
3. Remove the one (1) screw holding the exhaust  damper
assembly to the rear stay, and remove the exhaust
damper assembly by sliding it backward.
4. Remove the two (2) screws holding the oven (outer case
cabinet) to the top cabinet.
5. Remove the hood exhaust louver referring to...

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hood duct.
10.Remove the two (2) unit mounting screws from the
chassis support (right side) and the hood duct (left side).
11.Remove the one (1) screw holding the chassis support.
12.Remove the chassis support.
13.Remove the hood duct from the oven cavity by lifting it up
14.Screw the oven lamp off from the lamp socket.
15.Remove the lamp socket from the lamp angle.
16.Pull the wire leads from the oven lamp socket by pushing
the terminal hole of the oven lamp socket with the...