I'm very happy to see this video. I have on occasion heard complaints about reduced power in a microwave but have always assumed it was caused by a weak magnetron, diode or transformer, or some combination of the three. It's really nice to know that something this simple can have so much effect on its performance. Thank you for this.
Any kind of debris on that screen really hits the power.... Just think how much carbon is being wasted!! Thanks for watching if you can subscribe that would be helpful.
Making this fix produced a 20% reduction in the time required to bring water to a boil. The old one looked fine, but, clearly something had changed as the old mica cover was just slightly translucent while the new one was completely opaque to light. We timed several bring water to a boil moves both before and after the fix to objectively confirm the improvement. THANK-YOU !
Good job. Whilst you are at it turn the microwave over and make sure the cooling intakes are free of fluff. Nobody checks that but it impacts performance and reduces the life of the magnetron.
Okay I spent the first minute being like "I got chinese in the microwave right now and need the answer faster old man!" but then he showed why he liked his microwave, and I 100% agree that's a really cool way to set the time. Way better, and I imagine more reliable than the keypads.
Well I am so impressed by this. I brought my Aldi microwave new from Australia To Philippines 8 yrs ago. I accidentally dialed in 90 minutes instead of 90 seconds and went outside to do something. Well when i came back in everything was fried and red hot. I managed to get a second hand turntable but the paint was fried. I cleaned it up and tried it. Wow it still worsks great. But over time had to double heat time. I been thinking to buy new. But like you I really like the way this one works and its got a grill still works good. Man thank you so much! I tried what you said and it appears to have worked. I will leave the thing off for a couple of weeks and compare. What I have done is scrape the resedue off the plate with a knife, Im going to try that. See what happens. But thanks!
Good job Tom. It is funny how we men get attached to bits of kit. Someone pointed out that as Mica is s stratified solid that it is possible to split one sheet into two. I split a tenant's Mica cover into two with a sharp knife and it worked. Granted the bit I put back was thinner than the original but still stops splashes and steam getting into the wave guide.
❓❓❓ QUESTION : FROM U.S: my machine is 1000 wats and so many co.'s want y ou to only use 1100. sigh. Can the power be pushed up to 1100 by changing magnetron, or some other part? (I'm ignorant of all t his lol). Thanks
In my experience manufacturers play with the watt rating to gain sales. There are commercial microwaves that have a higher wattage. The output from microwave to microwave varies quite a bit. the magnetron is a tuned device and there is a wide spread of actual power output. A magnetron that happens to be spot on will produce 20% more RF power than its peers even though they roll off the production line with the same part number. Then they fade away quickly as they are used. I wouldn't fit a different magnetron as the power supply wont be man enough, and, there are lethal voltages inside the microwave that remain present for some while after the power is unplugged. A bloke down the road for me was messing with his and never came back in from the shed to eat his dinner never saw his lovely wife again.
I have a trusty Westinghouse microwave which has been working quite well for probably a little over 20 years now, recently it feels like it's losing power. Not by a lot, I think I'm adding maybe 20% cooking time. So I took a peak inside and it has two plastic covers where I expect the microwave window to be, no exposed mica. Since it's not exposed I assume it didn't get contaminated with food, maybe in my case magnetron is more likely?
The plastic covers you mention are unlikely to be the magnetron waveguide outlet. If the plastic were to get splashed the food it would carbonise and get very hot initiating the same process in the plastics hydrocarbons and cause a melt down and flare. With regard to the magnetron, yes, if the wave guide is free then the magnetron might be the culprit. Also have a look underneath the microwave. The vents can get almost completely blocked by fluff drastically reducing the cooling for the magnetron and the oven ventilation. The magnetron is unlikely to overheat on a short run but will on a longer cooking cycle. I wondered if the lack of ventilation allows water vapor to build up in the oven absorbing the microwaves before they hit the food but I don't think this is significant. Good luck with it.
@@razenby I tried to pry them open after posting the comment, they have clips that can only be opened from the other side though so I didn't remove them completely. I did pry them enough to see they each cover a small window with what looks like mica behind it (again only accessible by opening the unit completely), and the mica looks flawless. I don't know what kind of plastic they are, but I could clearly see one of those clips that have two flares to catch the chassis, so it gotta have some elasticity to it so it can't be ceramic but it also doesn't sound like metal. I also saw your other microwave-related video so I checked the vents but they're surprisingly clean, to the point where it outta be passive cooled.
My microwave blew its fuse after cooking corn on the cob. Replaced the fuse and it blew straight away. So I started testing and found the Capacitor bad. So I replaced it. Now it starts out, good and bright and sounds normal for about 4seconds, then gets really dim inside and the fans slow, and turn table slows. I replaced the magnetron with same result, then tried another transformer from another microwave. The rectifier tests good, and even the original transformer tests good at 160ohms when the repair manual says it should be "around 150ohm" so I'm guessing that's not it. The filament coil says "around 1ohm" and it tests at 2ohms so I'm guessing that's not it. Primary winding is at 0ohms, which is spot on. It still heats, but I'm really scratching my head on this one. Lol. No matter what I try, it still bogs down, with just a cup of water. But it does heat it. Also pulled the part on this video off, but no change
Hmm there are fatally dangerous voltages in the microwave so be very careful, Th rectifier could be breaking down or you may have some shorted turns on the transformer. The three or four seconds sound like it fails when teh magnetron starts conducting heater warms up. Have you tried it with the old magnetron? the magnetron is a tunes self resonant device. If for some reason it oscillating then it may draw a very large current as it turns into forward biased rectified thermionic tube.
@razenby I tested the transformer and tried another transformer from another microwave, as well as the new and old magnetron. It doesn't seem to make a difference. I'm done with this one tho. I pulled out all the parts I plan to keep, and I'm scrapping the rest. Lol. Thanks
Love the development of the magnetron in Cambridge in the middle years of WWII. Considering that in the 1920s the professor of electrical engineering at Cambridge confidently stated that "It is, and will be impossible in the future to generate frequencies above 30 megahertz" The Germans cottoned onto the magnetron but had real production issues as they had t machine the cavities to extremely fine, almost impossibly tight tolerances to get resonance. Whereas the Brits used a metal strips at the end that acted as a tweakable capacitor at the end of the magnetron cavities. Genius.
I'm very happy to see this video. I have on occasion heard complaints about reduced power in a microwave but have always assumed it was caused by a weak magnetron, diode or transformer, or some combination of the three. It's really nice to know that something this simple can have so much effect on its performance. Thank you for this.
Not sure if it woks for everyone but it did on ours.
You are "The Man"! Thank you for this. Mine was only plastic, I cleaned it and put it back. Works perfectly.
Any kind of debris on that screen really hits the power.... Just think how much carbon is being wasted!! Thanks for watching if you can subscribe that would be helpful.
Making this fix produced a 20% reduction in the time required to bring water to a boil. The old one looked fine, but, clearly something had changed as the old mica cover was just slightly translucent while the new one was completely opaque to light. We timed several bring water to a boil moves both before and after the fix to objectively confirm the improvement. THANK-YOU !
Good job. Whilst you are at it turn the microwave over and make sure the cooling intakes are free of fluff. Nobody checks that but it impacts performance and reduces the life of the magnetron.
Okay I spent the first minute being like "I got chinese in the microwave right now and need the answer faster old man!" but then he showed why he liked his microwave, and I 100% agree that's a really cool way to set the time. Way better, and I imagine more reliable than the keypads.
Thanks for the comment (I think!!). Enjoy your Chinese.
Well I am so impressed by this. I brought my Aldi microwave new from Australia To Philippines 8 yrs ago. I accidentally dialed in 90 minutes instead of 90 seconds and went outside to do something. Well when i came back in everything was fried and red hot. I managed to get a second hand turntable but the paint was fried. I cleaned it up and tried it. Wow it still worsks great. But over time had to double heat time. I been thinking to buy new. But like you I really like the way this one works and its got a grill still works good.
Man thank you so much! I tried what you said and it appears to have worked. I will leave the thing off for a couple of weeks and compare. What I have done is scrape the resedue off the plate with a knife, Im going to try that. See what happens. But thanks!
Good job Tom. It is funny how we men get attached to bits of kit. Someone pointed out that as Mica is s stratified solid that it is possible to split one sheet into two. I split a tenant's Mica cover into two with a sharp knife and it worked. Granted the bit I put back was thinner than the original but still stops splashes and steam getting into the wave guide.
Thank you, it is very helpful, I just, put the front side of the mica plate behind and the performance has improved remarkably
Glad it helped!
❓❓❓ QUESTION : FROM U.S: my machine is 1000 wats and so many co.'s want y ou to only use 1100. sigh. Can the power be pushed up to 1100 by changing magnetron, or some other part? (I'm ignorant of all t his lol). Thanks
In my experience manufacturers play with the watt rating to gain sales. There are commercial microwaves that have a higher wattage. The output from microwave to microwave varies quite a bit. the magnetron is a tuned device and there is a wide spread of actual power output. A magnetron that happens to be spot on will produce 20% more RF power than its peers even though they roll off the production line with the same part number. Then they fade away quickly as they are used. I wouldn't fit a different magnetron as the power supply wont be man enough, and, there are lethal voltages inside the microwave that remain present for some while after the power is unplugged. A bloke down the road for me was messing with his and never came back in from the shed to eat his dinner never saw his lovely wife again.
I have a trusty Westinghouse microwave which has been working quite well for probably a little over 20 years now, recently it feels like it's losing power. Not by a lot, I think I'm adding maybe 20% cooking time.
So I took a peak inside and it has two plastic covers where I expect the microwave window to be, no exposed mica. Since it's not exposed I assume it didn't get contaminated with food, maybe in my case magnetron is more likely?
The plastic covers you mention are unlikely to be the magnetron waveguide outlet. If the plastic were to get splashed the food it would carbonise and get very hot initiating the same process in the plastics hydrocarbons and cause a melt down and flare. With regard to the magnetron, yes, if the wave guide is free then the magnetron might be the culprit. Also have a look underneath the microwave. The vents can get almost completely blocked by fluff drastically reducing the cooling for the magnetron and the oven ventilation. The magnetron is unlikely to overheat on a short run but will on a longer cooking cycle. I wondered if the lack of ventilation allows water vapor to build up in the oven absorbing the microwaves before they hit the food but I don't think this is significant. Good luck with it.
@@razenby I tried to pry them open after posting the comment, they have clips that can only be opened from the other side though so I didn't remove them completely. I did pry them enough to see they each cover a small window with what looks like mica behind it (again only accessible by opening the unit completely), and the mica looks flawless.
I don't know what kind of plastic they are, but I could clearly see one of those clips that have two flares to catch the chassis, so it gotta have some elasticity to it so it can't be ceramic but it also doesn't sound like metal.
I also saw your other microwave-related video so I checked the vents but they're surprisingly clean, to the point where it outta be passive cooled.
Oh and it says "Multiwave" on it so I guess it makes sense for it to have two windows.
I actually just cleaned it and put it back in. The push pins popped out easy. Popped popcorn quicker!
Great Tip. thanks.
Why is it necessary to even replace that wave guide mica???
Ift gets fouled with carbon that attenuates the microwave energy from the Magnetron's wave guide.
That’s altogether different approach to microwave oven repairs. Thanks a lot
Our pleasure!
For the record, you can use the magnetron to take down the Greco.
Good idea..
if you remove the waveguide cover and don't cover your food or drink it can splash onto the magnetron and contaminate it so bad idea
Yes it is but is hasn't happened. It is just an illustration re the effect that a contaminated cover has on Microwave performance.
My microwave blew its fuse after cooking corn on the cob. Replaced the fuse and it blew straight away. So I started testing and found the Capacitor bad. So I replaced it. Now it starts out, good and bright and sounds normal for about 4seconds, then gets really dim inside and the fans slow, and turn table slows. I replaced the magnetron with same result, then tried another transformer from another microwave. The rectifier tests good, and even the original transformer tests good at 160ohms when the repair manual says it should be "around 150ohm" so I'm guessing that's not it. The filament coil says "around 1ohm" and it tests at 2ohms so I'm guessing that's not it. Primary winding is at 0ohms, which is spot on. It still heats, but I'm really scratching my head on this one. Lol. No matter what I try, it still bogs down, with just a cup of water. But it does heat it. Also pulled the part on this video off, but no change
Hmm there are fatally dangerous voltages in the microwave so be very careful, Th rectifier could be breaking down or you may have some shorted turns on the transformer. The three or four seconds sound like it fails when teh magnetron starts conducting heater warms up. Have you tried it with the old magnetron? the magnetron is a tunes self resonant device. If for some reason it oscillating then it may draw a very large current as it turns into forward biased rectified thermionic tube.
@razenby I tested the transformer and tried another transformer from another microwave, as well as the new and old magnetron. It doesn't seem to make a difference. I'm done with this one tho. I pulled out all the parts I plan to keep, and I'm scrapping the rest. Lol.
Thanks
Would it do harm if the cover was left out.
Possible food could spurt into the wave guide and affect performance.
Castles in the Sky is an Epic movie about radar with links to the magnetron
Love the development of the magnetron in Cambridge in the middle years of WWII. Considering that in the 1920s the professor of electrical engineering at Cambridge confidently stated that "It is, and will be impossible in the future to generate frequencies above 30 megahertz" The Germans cottoned onto the magnetron but had real production issues as they had t machine the cavities to extremely fine, almost impossibly tight tolerances to get resonance. Whereas the Brits used a metal strips at the end that acted as a tweakable capacitor at the end of the magnetron cavities. Genius.
Thank you sir
You are welcome. thank you for watching.
mi micro has plastic cover
Interesting...... Thanks.
Try splitting it into thinner peace !
Great idea!
Thank you😊
You're welcome 😊