Microwave Oven Membrane Keypad: The Inspection Guide

hqtSep 28, 2020

Step by Step Technique for Inspecting Your Microwave Oven Membrane Keypad

The microwave oven membrane keypad switch plays when it comes to operating the microwave oven. So, if something goes wrong with the membrane keypad, you will not be able to operate the machine. Therefore, you need to have the keypad intact.

There are different types of problems that can occur with the membrane keypad. We will not be covering every problem individually. On the contrary, we will offer a more generalized solution so that you can inspect your oven membrane keypad yourself. So, without any further delay, let’s begin.

A Comprehensive Inspection Guide

In case, the touchpad on your microwave open doesn’t respond, however, the display does light up, it means there is a problem with the membrane switch. The component that people generally refer to as the touchpad is basically a series of soft-touch electrical switches.

Microwave Oven Membrane Keypad

Membrane Keypad

It is important to understand the basic concept of a membrane keyboard, before you on inspecting and repairing one. To make things easy, a membrane keypad consists of pads or keys that have some sort of printed symbols on it.

The symbols can be alphabets, signs, numbers, etc. Although the keys seem individual, the keypad doesn’t contain individual keys. The entire pressure pad is without any breaks in it. It is more like a single surface that stretches out on the entire device.

Due to the single surface, the membrane keypad is compact in comparison to the mechanical keyboard. There are three important parts of the membrane keypads.

  1. The top layer. This layer consists of all the symbols.
  2. Then you have the middle layer. This is basically the inert.
  3. Lastly, we have the bottom layer. This layer is important is it is responsible for connecting the rest of the device.

There are numerous conductive traces present on the bottom layer. These traces are responsible for triggering the required command against every pressed symbol. There are two types of variation for a membrane keypad.

One is that comes with all symbols printed on the same pad. Whereas, the other one uses the dome design. IT means that the symbols would provide more tactile feedback. Mainly because they shape them into the domes.


One of the main reasons that a membrane keypad is more popular than its mechanical counterpart is its size. Membrane keypads are of small size, thus they fit nicely to the modern compact devices. They work well with gadgets with slimmer designs.

This is something the mechanical keypads cannot achieve. Moreover, the membrane switches do not have space in their keys, thus eliminating the chance of dust accumulation. This is something very important for medical devices. Also, these keypads are more robust and they have a long shelf-life.


The touchpad is the collaboration of soft-touch electrical switches. It has two layers of thin Mylar plastic. There is also the presence of conductive material in the inner surface of these layers. To keep the two coated surface separates, there is a formed gap between them.

The gap would stay intact until the user applies the pressure. The contact of the two conductive surfaces results in the completion of an electrical circuit. This then provides the control board with an input signal. When the conductive coating is used repeatedly it eventually wears out.

Thus, making it difficult to make good contact to send the input signal to the control board. If this is your problem, you would have to work on the coating layer.

Control Board of Oven membrane keypad

The Control board is often the main cause when the touchpad does respond, but the display lights up. After all, the control board is responsible for generating a low voltage. This voltage then transmits to the membrane switch.

The membrane would use these signals as the inputs and then would generate the respective output. These output replies are responsible for controlling a number of microwave components such as the magnetron, or the turntable motor.

So, when a control board is unable to generate the low voltage signal, it would lead to a lack of response of the touchpad. Likewise, the lack of a control board to sense the input would also result in the same problem.

Microwave Oven Membrane Keypad Problem

In order to start the inspecting process, we have listed the steps below.

  1. In order to gain access to the membrane switchof the microwave oven you would have to disconnect it by unplugging the unit.
  2. Make sure that the cord is out of the switch, instead of you turning only the switch button off while the cord remains plugged in.
  3. Next, you need to remove the cabinet of the microwave oven.
  4. You will find the membrane switch attached to the control panel, at the same time, it has a connection with the electronic control board as well via a connector. The connector has a flat ribbon style.
  5. Before you dig any deeper, check the connection. It is there is no problem with that, then you can go on testing the membrane switch.
  6. In order to test the continuity of the membrane switch, you would be using a multi-meter.
  7. See whether the ere is of only a few ohms of resistance against every touchpad you press.
  8. To perform the test, you would need the membrane switch’s matrix layout. The layout would be present in the electrical schematic.
  9. If are unable to find the problem, you would have to either reach out to replace the entire control board or contact the best membrane keypad repair service, provider.

Microwave Oven Membrane Keypad manufacturers

Take Away

Inspecting and identifying the problem related to a microwave oven membrane keypad might seem simple. However, if you are new to this and have no information, it is better to reach out to a reliable repair services provider.

For those who can identify the problem and they are searching for reliable membrane keypad providers, they should contact FD-Keypad Manufacturers. Their extensive experience in designing and developing high-quality membrane keypads would help you choose the best one for your device.