Microwave failure

[altivo]

Microwaves have weird failure modes. Our old Sharp has been working for a long time (more than 13 years I'm sure) but in the last year the light inside has been erratic. Sometimes would come on, sometimes not. Sunday morning as I was making breakfast, though, something else failed in a more spectacular mode. I had put some butter in there to melt for the pancake batter only to hear a buzzing sound like a chainsaw when it started up. I hit STOP immediately and opened it to look. The inside was full of smoke.

Apparently something that diffuses the microwave beam had failed. There's a square of some fibrous material in the wall of most microwaves that covers the mouth of the waveguide. We now had a rectangular hole about a quarter inch across burned in that stuff. I don't know enough to mess with the innards of one of these, and getting it wrong could be really dangerous. Likewise, finding someone to repair it would have cost more than what we spent to buy it years ago. So I looked around online to see what could be found locally, and we went to Sam's Club in Crystal Lake to get a new one for $170 or so.

Now we have to figure out what to do with the dead one. I'm reluctant to put it out for trash pickup for fear someone will take it and try to use it. I'm quite confident it is not safe to use any more. I guess it will have to sit here until the county has one of those hazardous materials collection days.

Comments

[keeganfox.livejournal.com]

If there's no appliance recycling program (tend to be in Europe), then would be inclined to cut the cord off right up against the appliance, and disassemble it. Recycle the steel, aluminum and glass; crush the rest and trash it.

$0.02. YMMV. Be careful of electrical components (short with insulated screwdriver or similar)

[mondhasen.livejournal.com]

We used our first microwave for close to twenty years. When it finally gave up the ghost I dragged it down the dirt driveway to the street (to scuff it up) and then cut off the cord. If anyone thought it was usable and was willing to rebuild it after that, I imagined they knew what they were getting into.

I cut the cords off all my old appliances for fear of the 'pickers' taking something which could be hazardous. Some of these, generally the heavy duty, three-prong numbers, I keep for 'spares.' Others I toss in recycle (I don't know if they'll try to capture the copper at the plant or just toss them out).

[bladehorse.livejournal.com]

It sounds like the gun has detuned and is out of frequency. They tend to crap out in power after 10 years or so anyways. Making the 500w into an actual heating of 100 w :p
the rest is waste heat.
Look up steel scrap yards in the area, as they are more than happy to take stuff like that. they just shred it and send it off to china to make another one in their backyard foundry. Any metal differences melt off at different temps, so they can recover most metals just by the melt point at the smelters.
I currently have a 1974 micro that is 1/2 rebiult (Amana Patent range) weighs about 110# and has chrome plated steel on it. the gun wore out enough that it took 4 minutes to boil a cup of water. My dad had a newer ge that I parted out and am kit bashing it into the old amana case. The new one is 1000 w. the old one was 550w. I would have just bought a new gun, but they are LONG out of the hidden parts store inventories. So now I have to attatch the new gun somehow to the old camlock system it had.

I dont know if your interested, but there are at least 3 interlock switches, a power transformer 120 to 20k v a rather big cap, and a good fuze block. (Yes I get the most out of Anything!

[bladehorse.livejournal.com]

Oh and that burned hole in the fiberboard is no problem(Except it will continue to burn.) Pull it out Its just there to stop food spray from working its way into the gun proper.
Make sure any metal in there is on the floor and walls only, or at least 1" off the plate. this will cause things to burn out in short order, But Im sure your used to the NO metal rule of years ago.

[lobowolf.livejournal.com]

Yeah, the one in my microwave has a small hole in it and it works fine. As you said, it's just a cover to keep food out of the Magnetron.

[lobowolf.livejournal.com]

Make an ATV transmitter out of it!!!

http://www.scribd.com/doc/14004815/atv-transmitter-from-a-microwave-oven

[calydor.livejournal.com]

As said, cut the cord all the way up at the base of the machine.

If you're feeling violent, smash the door with a hammer. No one's going to try to run it after that.

[jamesb]

As has been said. Cut the cord off and if possible, break the door off.

If you want to go further, use the back of an axe or a sledge hammer and give the case a good solid hit to take out the control buttons and/or display. The magnetron will be on this side and you may take it out as well.

I've had training on BIG RADAR systems, and have used knowledge from that to repair microwave ovens. Unless you have sentimental attachment or the microwave has a feature that you consider a "must have" and you can't get a replacement that has that feature, then a repair will cost more than a new oven.

[jamesb]

The magnetron is most likely "mode hopping".

[avon-deer.livejournal.com]

I tend to replace my microwave every eight years or so.

[animist.livejournal.com]

The new microwaves tend to be kind of nice if you shop around. And should be more efficient than the old one. I wouldn't wanna monkey around with any kind of High Frequency source that could be leaking radio waves anyway. Who knows where that waste energy is going and what it can do to you. If you are worried about someone fishing it out and using it (or more likely, reselling it cheap to innocent parties), I would take the door off of it and throw it away first. Send the rest out next week.

[schnee.livejournal.com]

I think my microwave's approaching 25 years (it's the first one my parents got, back in the mid-80s or so), but it's still working. They don't build 'em like they used to...

170 USD for a new one seems like quite a bit, but then, I've increasingly found that you get what you pay for, quality-wise, so it's probably best to invest a few more bucks. :)

Here's hoping that one will last longer.

[jmaynard.livejournal.com]

I had an analog-timer Sears microwave that I used for over 20 years, until it just got too weak. It's sitting in the basement now, holding up stuff. The voltages inside scare the ever-living hell out of me, and I'm not about to muck around with them. Fixing a microwave is as economically senseless these days as fixing a TV set.

[thedeere.livejournal.com]

That fibrous panel at the end of the waveguide protects the machine from grease vapor depositing grease up into the waveguide itself. They're cheap, 5-10 bucks, and common, especially for a Sharp. The thing failing was no doubt due to grease buildup on it letting it absorb energy, as it's in a high-flow area. Call around the electrical appliance repair shops, they'll sell ya one if you bring the old one in or tell 'em the model of yours. And yeah I'm a certified Sharp microwave tech. :)

Most of 'em remove by flexing them free of the metal tabs, some have a little plastic button which you pry the center-pin out from then pop the base out like a little plastic rivet. Good luck! :)

[altivo.livejournal.com]

Gary cut the cord off and put it out for the trash pickup last night. I didn't think he'd act so quickly, but it's gone, whether the scavengers took it or the actual waste removal truck.

[altivo.livejournal.com]

I checked. This one was 15 years old. The previous one had only lasted about 9 years. Both were the cheapest models we could get, though.

[altivo.livejournal.com]

I probably wouldn't have tried salvaging electronic parts, but thought about reusing the cabinet for something. Too late though. Gary moved fast for once and it went away with the trash early this morning. I'm not sure our waste disposal people would take it though, so someone else may have grabbed it.

[altivo.livejournal.com]

Amusing idea, though I have little interest in ATV myself. Thanks for the link.

[altivo.livejournal.com]

Gary cut the cord and put it out last night without my knowledge. It's gone now, though I remain unsure who took it. I think our regular weekly pickup would have left it behind.

[altivo.livejournal.com]

Yeah, the original price of this one was only $99 and it lasted 15 years. Not worth the cost of repair and as I said, I wasn't about to tackle it myself. Amusingly, Sharp had kept bugging me year after year to take out a maintenance contract for it. Cost of contract? $89/year! Had I done that, I'd have had $1200 or so invested in the thing before it failed, even if they did fix it for free at that point.

[altivo.livejournal.com]

This is only the second replacement we've ever done. I have a feeling we're on the way to our third bread machine though. Those get a lot more use than the microwave, actually, and have more mechanical parts. Cause of failure in the last one we had was actually ball bearing wear.

[altivo.livejournal.com]

Yeah, those were my thoughts. I'm sure it could have been fixed, but for the $99 I originally paid for it 15 years ago, and considering the additional improvements in the current models, just not worth it.

The new one has a larger capacity, slightly higher power, and a number of nice features the old one lacked.

[altivo.livejournal.com]

I expect this one will last at least as long. That price is about bottom of the scale for a full size unit. You can get smaller ones for as little as $69 or so.

[altivo.livejournal.com]

Voltage alone doesn't worry me as long as I know it's there. As a radio operator, though, I'm well aware of the risks of microwave frequencies and the fact that I don't have the technical knowledge or skill to be certain of the proper physical seals and fitting. $99 for 15 years of service seems acceptable, and it went in the trash. I dislike the waste issues there but as long as it costs more to recycle things than just to landfill them, this problem will continue.

[altivo.livejournal.com]

Yep, I actually had that out once trying to see if I could tighten or replace the light bulb. I don't think grease was an issue, the unit was very clean considering its age. (I get squicked by dirty microwave interiors.)

Thanks for the advice. I might have followed it, but Gary already dumped it with the trash, which was removed overnight. That's uncharacteristically fast for him, as he's usually a saver of old stuff, but anyway it's gone.