My microwave is not getting any power and the breaker is not tripped

William Miller

• 9179 Answers
• Posted on Jun 08, 2007

SOURCE: Microwave blows fuse

The most common suspects are the high voltage transformer and the magnetron. It's also possible you have a flaky door switch or loose door switch mount. If you or a friend decide to work on it, we have *critical* safety, disassembly, and troubleshooting info (as well as a text file which helps in diagnosing and repairing door switch problems) at our site, which is linked at our listing here on FixYa: http://tinyurl.com/yzjozk You can find helpful exploded view diagrams and order parts by entering your model number here: http://tinyurl.com/gv383

SOURCE: No power from Whirlpool.

The problem was a defective switch. There are 3 switches on mine. 1 on the top door latch, and 2 on the bottom. one of the switches on the bottom connected the power and neutral together, unless it was activated at the same time as the other 2, causing the breaker to trip or the internal fuse to blow. When unhooking the wire going from this switch to the other switch, everything works great now. Though I still need to replace the switch.

And for Basic 1. Yes my microwave did have a fuse in it it's ceramic, I got a pack of them at Radio Shack 4 for 3$ 250V 20 Amp. There should be a wiring diagram inside the microwave, mine was inside a black bag, so it may be hard to see.

Mine was up top next to the fuse behind the Plastic Grill and then a small metal grill. Some are behind the control panel, to fix this remove the screw at the top and then slide the control panel up and it should unhinge.

William Miller

• 9179 Answers
• Posted on Aug 08, 2008

SOURCE: LG microwave model MV1526B

The pop leads me to suspect that the high voltage rectifier diode blew.

We have the service manual for this model and have uploaded it to our site here to help you. You will need the free Adobe Reader to view or print it.

A microwave can be dead for many reasons.

It may be the fuse, which is usually located on the floor of the oven behind the control panel or between the door switches.

If the fuse is good, it may be an open thermostat or thermal cutout (TCO) / thermal fuse on or near the magnetron or on top of the cavity / body of the oven.

If it goes dead for a while during or after cooking then comes back on, the magnetron is probably overheating and causing the magnetron thermostat to open.

Then when it cools, it closes the circuit and allows power through again.

When checking thermostats, if it has a hood fan thermostat, that should read open, as opposed to the others, which should read closed.

If it went dead almost immediately after pressing the Start pad, that's usually a shorted high-voltage capacitor.

If it went dead a few seconds after pressing the Start pad, that's usually a failing high-voltage transformer.

If it goes dead or blows the breaker (or GFI) when you plug it in or open or close the door, then there's a problem with a door switch or door switch mount.

If it's intermittent or random, it may be a bad connection, usually on the control board or a loose fuse holder, or even an intermittent fuse.

You should do a continuity test on the fuse while it's in the holder (with the microwave unplugged, of course) then turn the fuse by hand or take it out and put it back in, then test it again.

If you remove the fuse, then press the meter leads against the ends, it can allow internal contact to be made and make a bad fuse appear to be good.

If you or someone you know decide to look into it, we have critical safety information and disassembly information at our site, and our link is at our listing here on FixYa.

There should also be a "mini-manual" hidden inside the unit behind the control panel or hidden on the left side behind the grille, which is very helpful when troubleshooting & testing.

You can usually find helpful exploded view diagrams and order parts by entering your full model number here.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

SOURCE: dead microwave

There are replacable fuses inside. Taking the microwave apart requires removal of a lot of screws and the cover that can be rather bulky. make sure it's unplugged and safe before you begin. you can get replacement fuses at radio shack, ect. be sure to buy the same type and amperage. if the blow a second time there may be other issues.

SOURCE: microwave power shut off and stopped working

You can test safety thermostats with an ohmmeter. There should be a short circuit between the device's two terminals if it's closed. (This doesn't necessarily mean the device is good, though. It might be opening at too low a temperature when the oven is operating.) A high resistance or an open circuit means the thermostat has opened and needs to be replaced. An appliance parts store should have suitable replacements, or you can order from a number of online vendors. I usually start at the Sears parts site. They have part information for many models, and usually pretty fair prices for parts. But once you have the part number you need, a Google search will let you shop around.

It does sound like your oven shut down because of a thermostat. One is normally mounted on the magnetron tube that supplies the microwaves, and another is on the cooking cavity. I've had to replace these many times. If the main power fuse blows the oven will not come back on until it's replaced. But you might also have bad solder connections causing the trouble as well. I've seen solder joints on the control board and power filter board cause dead ovens.

If you're not absolutely sure of what you're doing working on a microwave, you might want to let a professional check it over and make an estimate. There are potentially lethal voltages present, and microwave leakage may be a concern as well.