How To Fix a Microwave That Won’t Turn On
It could be a simple fix, or not. If it is, you are going to have to be a little handy, and it helps to have a multimeter and to know how to use one. When in doubt, call a professional or replace the unit.
The first thing is to check that it is properly plugged in, and to check the circuit breaker. You might want to try testing the outlet with another appliance before making a trip to the circuit box.
If all of that seems fine, the first thing to check will be the door latch. Has it been sticky? Has it been loose or not closing properly the first time? If the safety interlock on the door isn’t making proper contact, this will prevent the microwave from turning on. The reason is that the door must be properly closed in order to prevent stray microwaves from endangering your health. It is a safety feature.
Testing the Interlock Switch
1) Unplug the microwave.
2) Check the hooks that are on the door to make sure that they are not deformed. If they are, this can prevent the interlock switch from permitting the microwave to be turned on. You can think of the door hooks as being a kind of key that activates the interlock switch.
3) If the door hooks seem to be fine, and lining up properly with the interlock switch, you can remove the interlock switch by unscrewing it from the microwave.
4) Now set your multimeter to Rx1, turn it on, and touch the probes to the terminals. You should see a reading of “0” [zero], indicating that the circuit is continuous.
5) If your switch is not continuous, you can try spraying it with contact cleaner, thought that is likely a temporary solution. If it is not, you will want to get a replacement switch.
If you feel uncomfortable with any of these steps, you are probably best off contacting Dave’s Appliance instead of fixing it yourself.
Checking the Ceramic Fuse
If your microwave won’t start, and you can’t get a reading on the display, it could be that the ceramic fuse has blown. This fuse is there to protect the electrical components of your microwave from damage in case of power fluctuations. If the fuse is blown, nothing on your microwave will work until it is replaced.
1) Unplug the microwave.
2) Locate the fuse near the power cord. This may entail removing the microwave from its cabinet. Remove it.
3) As with testing the interlock switch, set your multimeter to Rx1, activate it, press the probes to both ends of the fuse. It should read “0” [zero]. If you don’t have a multimeter, and you happen to have a replacement fuse, though that is unlikely, you can try replacing it, but be very careful to make sure you have the proper replacement. You can also bring your fuse to a local electrical supply shop, and have them test it for you and get a replacement, if that is the problem.
Again, if any of the above makes you uncomfortable, it is best to seek professional help. The folks at Dave’s Appliance have seen these problems thousands of times, and can give you the advice you need.
For all other potential problems involving microwaves, you are best leaving things to the pros, unless you really have some good electrical problem-solving chops. Check to see whether your unit is still under warranty. Or maybe it’s just time to replace your microwave, although in many cases owners have become so accustomed to how a particular microwave works that they are reluctant to part with it. Or perhaps the microwave you have is part of a kitchen appliance ensemble that matches, and you don’t want to disrupt the way it hangs together.
At any rate, the helpful professionals at Dave’s Appliance are happy to advise you in the way that best suits your needs. Give them a call.