Where the fuse sits and why it blows
The fuse in a microwave is a small cylinder, usually about the size of your pinky finger, that sits inside the cabinet near the power cord or transformer. It stops the microwave from drawing too much current and burning out the whole unit. When a fuse blows, the microwave stops working entirely — no lights, no beeping, nothing.
A fuse blows because something inside the microwave is drawing more power than it should. This can happen if the magnetron (the part that makes heat) is failing, if the high-voltage capacitor is leaking, or if there is a short circuit somewhere in the wiring. Replacing the fuse alone will not fix the underlying problem — if the fuse blows again within a few weeks, the microwave has a deeper fault and needs a technician or replacement.
Key Takeaways
- The fuse is a small cylinder inside the microwave cabinet, usually near the power cord or transformer, and you must unplug the unit before touching anything inside.
- You need to know the fuse amperage rating (printed on the fuse itself) before you buy a replacement, because using the wrong amperage can damage the microwave or create a fire risk.
- The fuse holder is usually a clip or a cartridge socket that you can access by removing the cabinet cover, which typically requires a screwdriver and takes five to ten minutes.
- If the new fuse blows within a few weeks, the microwave has an electrical fault beyond the fuse and should be serviced or replaced rather than repaired repeatedly.
Unplug the microwave and let it discharge
Before you open the cabinet, unplug the microwave from the wall outlet. This is not optional — the high-voltage capacitor inside stores electrical charge even when the unit is off, and touching it can cause a serious shock.
After unplugging, wait at least five minutes. Then, using an insulated screwdriver (one with a plastic or rubber handle), touch the metal tip to both terminals of the high-voltage capacitor to discharge any remaining charge. The capacitor is usually a cylindrical component near the transformer. You will hear a small pop or see a spark — this is normal and means the capacitor is now safe to work around.
Remove the cabinet cover and locate the fuse
Most microwave cabinets are held together with screws on the back or sides. Use a Phillips or flathead screwdriver (depending on what your model uses) to remove these screws. Keep them in a small container so you do not lose them. Slide the cabinet cover off carefully — it may be tight, and you do not want to crack it.
Once the cover is off, look for the fuse. It is a small cylinder, usually white, ceramic, or plastic, with metal caps on both ends. The fuse is most often mounted near the power cord entry point or bolted to the transformer. You may see it labeled on the circuit board or in the owner's manual. If you cannot find it, check the manual for your specific model — fuse location varies.
Read the fuse amperage and buy the correct replacement
The amperage rating is printed on the fuse itself. It will say something like "15A" or "20A" (the A stands for amps). Write this number down. You also need to know the voltage — most household microwaves use 250V fuses, but check the fuse to be sure.
Go to an electronics store, hardware store, or online retailer and buy a replacement fuse with the exact same amperage and voltage. Do not guess or buy a higher amperage fuse thinking it will be safer — a fuse that is too large will not blow when it should, and the microwave can overheat or catch fire. A fuse that is too small will blow when ready even under normal use.
Remove the old fuse and install the new one
The fuse is held in place by either a clip holder or a cartridge socket. If it is a clip holder, gently pry the fuse out with a flathead screwdriver or your fingernail — do not force it. If it is a cartridge socket, the fuse may twist out or slide out depending on the design. Check your manual if you are unsure.
Once the old fuse is out, slide or twist the new fuse into place. Make sure it sits flush and is held firmly by the clip or socket. Do not overtighten — the fuse should be snug but not forced. If the fuse does not fit easily, you may have the wrong amperage or voltage, so stop and double-check before forcing it in.
Reassemble the microwave and test it
Slide the cabinet cover back on and screw it down with the screws you removed earlier. Make sure all screws are tight so the cover does not rattle or come loose during use.
Plug the microwave back in and turn it on. If it powers up normally — lights come on, the turntable spins, the control panel responds — the fuse replacement worked. If the microwave still does not turn on, the problem is not the fuse, and you should stop here and consider having it serviced or replaced.
What to do if the fuse blows again
If the new fuse works for a few weeks or months and then blows again, the microwave has an electrical fault that a new fuse cannot fix. This usually means the magnetron, capacitor, or transformer is failing. Replacing the fuse repeatedly is a temporary fix that masks a deeper problem.
At this point, you have two choices: pay a technician to diagnose and repair the fault (which often costs $150 to $300 or more), or replace the microwave. For most people, a new microwave is the better choice, because the repair cost is often close to the price of a new unit, and a new microwave comes with a warranty.
Frequently Asked Questions
Can I use a higher amperage fuse if I do not have the exact one?
No. A higher amperage fuse will not blow when it should, and the microwave can overheat, damage internal components, or catch fire. Always use the exact amperage printed on the old fuse. If you cannot find the right one locally, order it online rather than substituting.
Is it safe to replace the fuse myself?
Yes, if you unplug the microwave first and discharge the capacitor. The fuse itself is not dangerous to handle. The danger is the electrical charge in the capacitor, which is why the five-minute wait and the screwdriver discharge step are important.
What if I cannot find the fuse in my microwave?
Check your owner's manual — it will show the fuse location for your specific model. If you do not have the manual, search online for your microwave model number plus "fuse location". If you still cannot find it after checking the manual, the microwave may not have a user-replaceable fuse, and you should contact a technician.
How much does a replacement fuse cost?
A microwave fuse typically costs between $5 and $15, depending on the amperage and where you buy it. Electronics stores and online retailers both carry them. This is much cheaper than a service call or a new microwave, which is why replacing the fuse is worth trying if it has blown.