Why Is My Microwave Display Dim? 6 Causes + How to Fix

If you’ve ever had a dim microwave display, then you know how annoying it can be. While your microwave works fine without a bright digital display, you might not be able to tell how much time or heat is being used.

Your microwave display is dim because the high-voltage capacitor is failing, the wires aren’t secure in their terminals on the control board, or the control board is malfunctioning. The display might be damaged, or the brightness might be set too low. Make sure the light bulb is tight in its socket.

In this article, I’m going to explain why your microwave display is dim with the six most common causes and solutions.

Worn High-Voltage Capacitor

Every microwave has a high-voltage capacitor that carries a lot of electricity, even if the microwave isn’t plugged in. This capacitor acts as a battery that holds power from the wall outlet. It also powers the display (as well as a few other parts).

If the capacitor is damaged or failing, the microwave display will look dim and dull. It might also flash or blink. A worn high-voltage capacitor can also make your microwave whistle.

How to Fix

Follow these steps to fix a microwave’s high-voltage capacitor to fix the dim display:

1. Unplug the microwave from the wall.
2. Remove the rear panel from the microwave.
3. Discharge the high-voltage capacitor to prevent it from shocking you.
4. Remove the wires from both sides of the capacitor, then connect them to a new high-voltage capacitor from the microwave’s parts guide.
5. Plug in the microwave, then turn it on and check if the display is dim or bright.

Faulty Board Wire Terminals

Almost all wires eventually loosen from their terminals, regardless of the appliance. The Spruce explains that loose wires don’t supply enough power to the control board, which prevents them from illuminating the display. This problem will worsen until you tighten the wires (or replace them).

How to Fix

Here’s a handful of ways you can restore your microwave’s bright display:

• Remove the control board panel to reveal the control board (it’s on the side, back, or front of the microwave), then tighten each of its wires.
• Replace the display’s wires if they’re torn, rusted, or stripped too far back from the control board’s terminals.
• Tighten each of the wires on the back of the microwave’s display.

You could also try plugging the microwave into the wall and testing the circuit breaker’s electrical current. It should measure 120 volts or 220 volts, depending on the breaker’s voltage rating. If it’s not generating enough power, your microwave display will look dim.

Malfunctioning Control Board

The control board communicates and sends power to several parts of the microwave, including the display. If the control board doesn’t work properly, the microwave’s display will look dull. I’ve also noticed that a damaged control board will stop the microwave fan from working as it should.

How to Fix

Replace your microwave’s control board with these instructions:

1. Unplug the microwave or turn off the circuit breaker for mounted appliances.
2. Remove the control board panel, then disconnect each of the wires from the control board (it helps to label them or take a picture to know where they’re supposed to go).
3. Get a control board part number from the user’s manual, then find a like-for-like board.
4. Connect the wires to the correct terminals as listed in the second step.
5. Cover the control board with its panel, then plug the microwave in and turn it on.

Reduced Display Brightness Settings

Some microwaves have brightness settings. If your display’s brightness is set to the lowest setting, it’ll be dim and hard to read. Brightness adjustments can make your TV picture look unclear, blur your microwave’s digital display, and more.

How to Fix

If this is the case, all you have to do is turn up your microwave’s display brightness. Most microwaves with brightness settings have up and down arrows. If your microwave doesn’t have these, you might need to press multiple buttons at the same time to increase or decrease the brightness.

I suggest contacting the manufacturer to learn how you can increase the microwave’s brightness. These adjustments usually only apply to new microwaves. If the display dims over time, your microwave likely needs a display replacement.

Broken Microwave Display

Microwave displays break from time to time. This can happen if you accidentally drop something sharp or jagged on the display, but it can also happen gradually from wear and tear. Microwave displays typically last between five to ten years.

How to Fix

Thankfully, ARS Repair shows you can replace a microwave’s display by adding a new membrane with a display and all of the required buttons.

Try this method to replace your microwave’s dim display:

1. Make sure there’s no power going to your microwave.
2. Remove the panel screws behind the dim display.
3. Disconnect the hot and neutral wires from the back of the display, then peel the display membrane off of the microwave.
4. Connect the wires to the new display, then stick it on the front to the front of the microwave (some displays have to be screwed onto the microwave).
5. Turn on your microwave and make sure the display looks bright.

Dim Microwave Light Bulb

Does your microwave look darker than usual? This is often caused by microwaves without lights or displays. It can make the microwave display look dimmer than it normally does, preventing you from knowing how much time or heat it’s using.

How to Fix

Replace the microwave’s light bulb with this process:

1. Open the front of your microwave and locate the light bulb.
2. Unscrew the light bulb from its socket, then choose a light bulb with the same wattage.
3. Twist the new light bulb into the socket in the microwave.
4. Close the microwave door and check the display to see if it’s dim, dull, or bright.

If you’ve tried all of these suggestions, you’ll likely need to contact an appliance repair shop or replace the microwave. Microwaves can last up to a decade or more, but they eventually stop working (regardless of which repairs you try).