Panasonic NE-2157CR, NE-1757CR, NE-1257CR manual Component Test Procedure

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NE-1257R/NE-1257CR / NE-1757R/NE-1757CR / NE-2157R/NE-2157CR / NE-1258R

19 COMPONENT TEST PROCEDURE

19.1. High voltage transformer

1.Remove connections from the transformer terminals and check continuity.

2.Normal (cold) resistance readings should be as follows: Secondary winding Approx. 80Ω —120Ω

Filament winding Approx. 0Ω Primary winding Approx. 0Ω —3Ω

19.2. High voltage capacitor

1.Check continuity of capacitor with meter on highest OHM scale.

2.A normal capacitor will show continuity for a short time, and then indicate 9MΩ once the capacitor is charged.

3.A shorted capacitor will show continuous continuity.

4.An open capacitor will show constant 9MΩ .

5.Resistance between each terminal and chassis should be infinite.

19.3. Magnetron

Continuity checks can only indicate an open filament or a shorted magnetron. To diagnose for an open filament or shorted magnetron.

1.Isolate magnetron from the circuit by disconnecting the leads.

2.A continuity check across magnetron filament terminals should indicate one ohm or less.

3.A continuity check between each filament terminal and magnetron case should read open.

19.4. Diode

1.Isolate the diode from the circuit by disconnecting the leads.

2.With the ohmmeter set on the highest resistance scale, measure the resistance across the diode terminals. Reverse the meter leads and again observe the resistance reading. Meter with 6V, 9V or higher voltage batteries should be used to check the front-to-back resistance of the diode, otherwise an infinite resistance may be read in both directions.

A normal diode's resistance will be infinite in one direction and several hundred kΩ in the other direction.

19.5.Membrane key board (Membrane switch assembly)

Check continuity between switch terminals, by tapping an appropriate pad on the key board. The contacts assignment of the respective pads on the key board is as shown in digital programmer circuit.

19.6. Protector diode

1.Isolate the protector diode assembly from the circuit by disconnecting its leads.

2.With the ohmmeter set on the highest resistance scale, measure the resistance across the protector diode terminals.

Reverse the meter leads and again observe the resistance reading. A normal protector diode's resistance will be infinite in both directions. It is faulty if it shows continuity in

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Contents Commercial Microwave Oven Contents Page Outline Diagram Operation Procedure Page Page Page Page Wiring Requirements and Power Source Voltage Selection Wiring RequirementsSchematic Diagram NE-1257R, NE-1258R Schematic Diagram NE-1257CR Schematic Diagram NE-1757R Schematic Diagram NE-1757CR Schematic Diagram NE-2157R Schematic Diagram NE-2157CR Wiring Diagram NE-1257R, NE-1258R Wiring Diagram NE-1257CR Wiring Diagram NE-1757R Wiring Diagram NE-1757CR Wiring Diagram NE-2157R Wiring Diagram NE-2157CR Variable power cooking control Description of Operating SequenceCheck the grounding Confirm after repair Disassembly and Parts Replacement Procedure Replacement of magnetrons Upper and LowerReplacement of power supply circuit board Removal of Positive Lock connectorReplacement of upper antenna Replacement of floor shelf and lower antennaReplacement of temperature sensor Thermal protector Disassembly of door assembly Component Test Procedure Temp sensor Thermal protector Measurements and Adjustments Measurement of microwave outputProcedure for Measuring Microwave Energy Leakage EquipmentPage Troubleshooting Guide Exploded View and Parts List Parts List High Voltage LabelDoor Hook a Spacer a Door Assembly Escutcheon Base Assembly Packing and Accessories Wiring Material 29 REF. no L. V. Transformer U 30 REF. no Noise Filter U31 REF. NO. E2 P. C. Board U Schematic Diagram Digital Programmer CircuitPage Parts List

NE-1257CR, NE-1757CR, NE-2157CR specifications

The Panasonic NE-2157CR, NE-1257CR, and NE-1757CR are three professional commercial microwaves designed for robust food service operations. These models are widely appreciated for their versatility, efficiency, and user-friendliness, making them ideal for restaurants, cafes, and food trucks.

The NE-2157CR stands out with its powerful 1500 watts of cooking power, which ensures quick and uniform heating of various food items. It features a large 0.9 cubic feet internal capacity, allowing users to accommodate larger dishes. One of the key highlights of this model is its programmable memory with up to 20 customizable settings, which enables users to recall frequently used cooking times and power levels easily. The stainless steel exterior and interior ensure durability and ease of cleaning, while the touch control panel provides a simple interface for quick operation.

Next in the line is the Panasonic NE-1257CR, which offers a slightly lower power output at 1200 watts, making it a more compact option while still delivering impressive cooking results. With a capacity of 0.8 cubic feet, it is an excellent choice for smaller kitchens that require efficiency without sacrificing quality. Its easy-to-use interface allows for basic cooking functions, while the stainless steel construction guarantees longevity in busy environments.

Finally, the NE-1757CR is a middle ground between the two, featuring 1700 watts of cooking power and an internal capacity of 0.6 cubic feet. This model combines performance with a smaller footprint, making it a versatile choice for various commercial settings. Like its counterparts, the NE-1757CR includes programmable presets and a user-friendly control panel, offering consistent results with minimal effort.

All three models utilize Panasonic's advanced inverter technology, which provides consistent heat and eliminates cold spots. This technology allows for more precise temperature control and helps preserve the texture and moisture of food during cooking.

In summary, the Panasonic NE-2157CR, NE-1257CR, and NE-1757CR are all excellent options for commercial kitchens looking for reliable, efficient microwaves. With their robust construction, user-friendly controls, and advanced cooking technologies, these models cater to a wide range of food preparation needs, enhancing productivity in any food service operation.
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