How to Change Fuse in LG Microwave (Save Your Appliance)

You walked into the kitchen, pushed the start button, and absolutely nothing happened. The lights stayed off, the hum never started, and your leftovers stayed cold. It is a sinking feeling. I have been there plenty of times with my own gear. You do not need to call a pro or buy a new unit just yet. Most of the time, this is a simple fuse failure that you can handle in your own kitchen with a few basic tools and some patience.

You need to unplug the unit first. Do not skip this. Once it is unplugged, unscrew the outer metal shell. Find the fuse holder, usually near the power cord entry, and pop it out. Swap the old fuse for a new one with the exact same rating. Put the cover back on, plug it in, and test it.

Why Your Microwave Keeps Stopping

Microwaves are pretty sturdy machines, but they rely on safety parts to keep from starting a fire or frying the internal electronics if there is a power spike.

Electrical Power Surges

A sudden jump in voltage from a lightning strike or a grid issue hits the machine hard. The fuse acts like a shield. It breaks the circuit to protect the sensitive internal components from getting roasted by that extra energy. If your microwave went dark after a storm, a blown fuse is the most likely culprit behind the silence.

Door Switch Problems

The door switches tell the unit it is safe to cook. If these switches fail or get misaligned, they can cause a short circuit. This often blows the fuse instantly as a safety measure. If your door feels loose or does not click shut, the door switch assembly might be the reason your fuse keeps dying.

Capacitor Discharge Issues

The high-voltage capacitor stores a lot of energy. If it shorts out, the surge is massive. This is a very common cause for a microwave not turning on suddenly. You have to be careful here. Even when unplugged, a capacitor can hold a lethal charge, so you must discharge it before you start poking around.

Component Age Wear

Parts just wear out over time. The insulation on wires can crack and lead to shorts. Internal fans can seize up and draw too much power. When the machine has been used for years, these minor failures add up. A blown fuse is often just a symptom of an aging control board or motor.

Incorrect Usage Habits

Using the microwave to heat items for way too long or jamming it full of dense food can put a strain on the magnetron. This excessive draw can pop a fuse if the unit is already struggling. I learned the hard way that overloading the magnetron is a quick ticket to a dead appliance.

Poor Ventilation Space

Microwaves need room to breathe. If the vents are blocked by dust or cabinets, the heat builds up inside. This heat makes components fail faster and increases the risk of a blown fuse. Always keep those air intake vents clear so the internal cooling system can do its job correctly without blowing a fuse.

Actually, let me back up a second. Before you start, check if your kitchen outlet has tripped its own breaker. It sounds obvious, but I once spent an hour pulling a microwave apart only to find the wall outlet was the only problem.

• Check the wall breaker first.
• Use a flashlight for dark corners.
• Wear dry rubber-soled shoes.
• Keep all screws in one bowl.
• Verify the fuse rating numbers.
• Discharge the capacitor carefully.

Steps for Replacing the Microwave Fuse

Replacing a fuse is very straightforward once you get the case open. You just need to be slow and steady. Take your time, stay organized, and you will have it running again.

Prepare the Unit

Unplug your microwave from the wall outlet before you do anything else. This is not just a suggestion. It is the only way to keep yourself safe from a serious shock. Grab your screwdriver and set it on the counter. You will need a Phillips head driver for most LG models to remove the screws.

Clear off your workspace so you have plenty of room to lay the machine down. Lay a towel or a soft mat on the counter to protect the finish of the microwave. You do not want to scratch the stainless steel while you are working. Keep a small cup nearby to hold all the little screws.

Once the area is clear, look at the back and sides of the unit. There are usually screws holding the outer metal cover in place. Remove these carefully. If the screws are tight, use a bit of pressure to turn them without stripping the heads. Keep everything organized so you can put it back.

Locate the Fuse

With the cover off, you will see a maze of wires, a big fan, and a metal box. The fuse is usually tucked inside a plastic holder near where the power cord enters the unit. Look for a pair of wires coming from the power cord that lead to a small cylinder. That is your target.

The fuse holder might be clipped to the frame or just sitting near the high-voltage transformer. It looks like a small plastic tube or a black box that twists open. Use your flashlight to confirm you have found the right part. It should look like a glass or ceramic tube inside a holder.

If you are not sure, follow the power cord lead. The fuse is almost always in series with the live wire. Do not touch the big silver capacitor yet. Keep your hands away from the high-voltage areas. Just look for the fuse housing and make sure you have enough space to reach it safely.

Remove the Old Fuse

Gently twist the fuse holder cap or unclip the housing to expose the fuse. If it is a glass fuse, you might be able to see if the wire inside is broken or charred. A dark or cloudy glass tube is a clear sign that the fuse has done its job and burned out.

Use a pair of needle-nose pliers if the fuse is stuck. Be very gentle so you do not break the glass in your fingers. You just need to pull it straight out of the clips. Sometimes the clips are tight, so give it a steady pull without yanking. Take it out and set it aside.

Compare the old fuse with your new one before you go any further. The numbers printed on the metal cap must match exactly. If the voltage or amperage is different, it will not work properly. Using the wrong fuse can lead to a fire or further damage to the microwave board.

Insert the New Fuse

Slide the new fuse into the clips where the old one lived. It should snap into place with a light click. Make sure it sits firmly in the center of the clips. If the clips look loose or bent, you can lightly pinch them to make sure they hold the new fuse tight.

Check that the fuse is clean and free of any debris or dust. If you see any black soot around the area, wipe it away with a dry cloth. Do not use any liquid cleaners inside the case. Everything must be completely dry before you close the unit back up and plug it in.

Once the fuse is seated, put the plastic holder or cap back on. Ensure it is locked or screwed in place so it does not rattle. Check the wires one last time to make sure they are still connected correctly to the holder. You want everything to look exactly like it did before.

Close the Case

Carefully slide the metal cover back over the unit. Line up the screw holes perfectly. This can be tricky, so take your time. Do not force it if it does not want to sit flush. If a screw does not go in, back it out and try again to avoid stripping the metal holes.

Replace all the screws you removed earlier. Start with the ones on the back, then tighten the ones on the sides. Use your screwdriver to make them snug, but do not overtighten them. You just want them to hold the shell securely in place so it does not vibrate during use.

Take a look at the unit to ensure no wires are pinched under the cover. A pinched wire can cause a new short and blow your brand-new fuse instantly. If everything looks good, you are ready to test the microwave. It should be as good as new once you plug it back in.

Test the Microwave

Plug the microwave back into the wall outlet. If it is a built-in model, slide it back into its cubby carefully. Watch out for the power cord so it does not get crushed. Once it is pushed in, you should see the display light up immediately. That is a great sign.

Place a cup of water inside and set the timer for thirty seconds. Press start. If it hums and the light comes on, you fixed the problem. If it runs for a few seconds and then quits, you might have a deeper issue like a shorted magnetron or a bad door switch assembly.

If the microwave works, you saved a lot of money on a repair bill. Keep the model number saved in your phone in case you need parts in the future. Now you know how to handle the most common issue with these machines. It feels good to fix something yourself.

• Unplug the unit before starting.
• Discharge the high-voltage capacitor.
• Match the fuse amperage rating.
• Inspect clips for loose tension.
• Keep the work area dry.
• Test with a cup of water.

Changing a fuse is a great way to learn how your kitchen gear works. Just remember that safety comes first every single time. If you feel unsure at any point, stop and call a professional. It is never worth the risk of a dangerous shock.

Is a Blown Fuse a Sign of a Bigger Problem?

Most of the time, a fuse blows because of a power surge or a minor hiccup in the electrical flow. It is just doing its job. However, if your new fuse blows immediately, you definitely have a short somewhere else.

I had this happen once. I changed the fuse, and it popped the moment I closed the door. It turned out to be a faulty door switch. That switch was a three-dollar part that caused a massive headache. If you replace the fuse and it keeps blowing, stop and check the door switches and the capacitor integrity.

• Check for burnt wires.
• Test door switch continuity.
• Look for capacitor leaks.
• Check the magnetron connections.
• Verify the wall outlet.
• Inspect the control board.

How Do I Know Which Fuse to Buy?

You have to look at the old fuse. The specs are printed on the metal end caps. You will see numbers for amps and voltage. You must match these numbers exactly. If the microwave calls for a 20-amp fuse, do not use a 15-amp or a 25-amp one.

Using the wrong size is dangerous. A fuse that is too weak will blow right away. A fuse that is too strong will not protect the unit during a surge, which could lead to a fire. I always suggest buying a multi-pack of the exact fuse rating so you have spares on hand for the future.

• Read the end cap.
• Match the amperage rating.
• Check the voltage rating.
• Match the physical size.
• Look for ceramic vs glass.
• Check the manufacturer manual.

Should I Always Unplug the Microwave?

Yes, absolutely. Never skip this. Even if the microwave is not turned on, there is still power running to the internal components. Touching the wrong wire can give you a painful shock. Always pull the plug from the wall.

If your microwave is a built-in model that is hard to reach, flip the circuit breaker at your main electrical panel. Make sure you turn off the right one. Use a non-contact voltage tester to verify the power is off before you pull off the outer case. That is how you keep yourself safe from electrical shock.

• Pull the wall plug.
• Flip the home breaker.
• Use a voltage tester.
• Wait for discharge time.
• Keep tools on dry surfaces.
• Wear rubber-soled shoes.

Can I Use a Paperclip As a Temporary Fuse?

Please do not do this. I have heard people talk about wrapping a fuse in foil or using a paperclip to get the microwave working for one more night. This is a fire waiting to happen. It removes the only safety barrier your microwave has against a major electrical fire.

A fuse is designed to melt and break a circuit under specific conditions. A piece of metal will not do that. Instead, it will let the current keep flowing until the internal wires melt or the whole board catches fire. Just wait until you can get the right part. It is not worth the risk of burning down your house.

• Never bypass safety parts.
• Foil is a fire hazard.
• Paperclips cause overheating.
• Wait for proper parts.
• Safety is worth the wait.
• Avoid DIY permanent hacks.

Final Thoughts

I hope this guide helps you get your kitchen back to normal. Fixing a microwave fuse is one of those tasks that feels intimidating until you actually do it. Once you see how simple the internals are, you will feel much more confident next time something stops working. Just remember to move slow, keep track of your screws, and always unplug the power. You can do this.

Frequently Asked Questions

Is It Hard to Change an LG Microwave Fuse?

It is not hard, but it requires caution. If you have a screwdriver and can follow directions, you can do it in about twenty minutes. The hardest part is simply getting the metal cover off without bending it.

Can I Fix a Microwave Without Calling a Repairman?

Yes, you can fix many common issues yourself. Replacing a fuse, a light bulb, or a simple door switch is well within the reach of most home cooks. Just be sure to always unplug the unit first.

Are All Microwave Fuses the Same Size?

No, they are not. You must check the specific numbers printed on your fuse caps. Manufacturers use different ratings based on the power output and design of the microwave. Always match the exact part number.

Does a Blown Fuse Mean the Magnetron is Broken?

Not always. A blown fuse often happens because of a surge or a bad switch. However, if the fuse blows again immediately after you replace it, that is a strong sign of a shorted magnetron or a bad capacitor.

Should I Wear Gloves When Working on the Microwave?

Gloves can help with grip, but they do not replace the need to unplug the machine. If you are worried about sharp metal edges inside the case, a pair of thin work gloves is a good idea to prevent small cuts.

Will the Microwave Work If I Bypass the Fuse?

Technically, it might work, but you should never do it. The fuse is there to prevent fire and electrical damage. If you bypass it, you remove the only safety mechanism that protects your home from a potential disaster.

How Do I Know If the Fuse is Actually Blown?

Most fuses are glass, so you can see the thin wire inside. If that wire is snapped or the glass looks dark and cloudy, it is blown. If you are unsure, a cheap multimeter can test for continuity.

Can I Buy a Fuse at a Hardware Store?

You can find some standard fuses at local stores, but microwave fuses are often specific. I recommend checking the model number of your microwave online to find the exact replacement part to ensure it fits and works correctly.