NOISE FILTER

R-22AT

R-24AT

 

TEST PROCEDURES

PROCEDURE

 

LETTER

COMPONENT TEST

 

If the meter does not indicate above resistance, replace the thermistor.

 

3. CARRY OUT 4R CHECKS.

JMOTOR WINDING TEST

CARRY OUT 3D CHECKS.

Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two terminals.

Resistance of Blower motor should be approximately 60.

Resistance of Antenna motor should be approximately 8.8 k.

If incorrect readings are obtained, replace the motor.

CARRY OUT 4R CHECKS.

KNOISE FILTER TEST

CARRY OUT 3D CHECKS.

Disconnect the leads from the terminals of noise filter. Using an ohmmeter, check between the terminals as described in the following table.

MEASURING POINT

INDICATION OF OHMMETER

Between N and L

Approx. 680 k

 

 

Between terminal N and WHIT

Short circuit

 

 

Between terminal L and BLK

Short circuit

If incorrect readings are absorbed, replace the noise filter.

CARRY OUT 4R CHECKS.

N

L

 

F3 : WEAK POINT

 

NOISE SUPPRESSION COIL

DISCHARGE RESISTOR 680 k1/2W

LINE CROSS CAPACITOR 0.22F/ AC250V

 

DISCHARGE RESISTOR 10 M1/2W

LINE CROSS CAPACITOR

LINE CROSS CAPACITOR

10000 pF/ AC250V

10000 pF/ AC250V

WHT

BLK

LHIGH VOLTAGE FUSE F4, F5 TEST CARRY OUT 3D CHECKS.

If the high voltage fuse F4 (or F5) is blown, there could be a short in the high voltage rectifier or the magnetron MG1 (or MG2). Check them and replace the defective parts and the high voltage fuse F4 (or F5).

CARRY OUT 4R CHECKS.

CAUTION: Only replace high voltage fuse with the correct value replacement.

MTOUCH CONTROL PANEL ASSEMBLY TEST

The touch control panel consists of circuits including semiconductors such as LSI, IC, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter. In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key Unit, troubleshooting by unit replacement is described according to the symptoms indicated.

1. Key Unit Note : Check key unit ribbon connection before replacement. 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 the pads, sometimes a pad produces no signal.

2.Control Unit

The following symptoms may indicate a defective control unit. Replacing the control unit. Before replacing the control unit, perform the key unit test (Procedure N) to determine if control unit is faulty.

2-1 Programming problems.

a)When touching the pads, a certain group of pads do not produce a signal. 2-2 Display problems.

a)For a certain digit, all or some segments do not light up.

b)For 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.

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Sharp R-22AT, R-24AT service manual Motor Winding Test, Noise Filter Test, High Voltage Fuse F4, F5 Test Carry OUT 3D Checks

R-22AT, R-24AT specifications

The Sharp R-24AT and R-22AT microwave ovens are advanced kitchen appliances designed to enhance cooking convenience, efficiency, and versatility. Both models incorporate innovative technologies and features that cater to modern cooking needs.

The Sharp R-24AT boasts a robust 900 watts of cooking power, enabling users to prepare a wide variety of meals quickly and effectively. Its spacious 24-liter capacity is suitable for families and those who enjoy entertaining. One of the standout features of the R-24AT is its intelligent sensor technology, which automatically detects humidity levels in the cooking food. This innovative feature ensures optimal cooking times and temperatures, resulting in perfectly cooked dishes without the guesswork.

Another key technology in the R-24AT is the inverter cooking system. This system provides a seamless flow of power throughout the cooking process, allowing for more precise temperature control. Unlike traditional microwaves that operate in full power or off, inverter technology ensures consistent heat, which is particularly beneficial for tasks such as defrosting, reheating, and simmering.

The Sharp R-22AT, while slightly more compact with a 22-liter capacity, also delivers impressive performance with 800 watts of power. It features a similar inverter cooking system that guarantees even cooking results. Both models come with multiple auto-cook presets, providing users with a selection of quick options for common dishes such as popcorn, pizza, and oatmeal. This feature streamlines meal preparation and reduces the time spent on planning meals.

In addition, the user-friendly control panel on both models includes a combination of push-button and rotary dial controls for easy navigation. The inclusion of a bright LED display further enhances usability, allowing cooks to monitor cooking times and settings easily.

Safety is another critical aspect of the Sharp R-24AT and R-22AT. Both models come equipped with a child lock feature, ensuring peace of mind in homes with young children. The stainless steel interiors of these microwaves facilitate easy cleaning, while their sleek design adds a modern touch to any kitchen.

In summary, the Sharp R-24AT and R-22AT microwave ovens stand out for their advanced cooking technologies, user-friendly features, and thoughtful design. They empower home cooks to prepare meals with precision and ease, making them a valuable addition to any kitchen.